But as we accept the notion that the horrific attacks on the Pentagon and World Trade Center on Sept. 11 have changed our world irrevocably, Bono looks better than ever; his earnestness suddenly feels a lot less corny. It’s not to say that he has all the answers, but once again celebrities who crusade have less reason to fear ridicule. The great thing about Bono, though, is that he probably doesn’t care whether he looks cool along the way.

Bono’s humanitarianism has always been purchased on the credit line of U2′s fame, which is precisely why it has made a noticeable return in the last year. Many U2 fans (and rumor has it even Bono and his band mates) had speculated that the band’s best days were behind them. But now U2 have suddenly made their best album in a decade. “All That You Can’t Leave Behind,” released in fall of 2000, has received nearly unanimous critical acclaim and sold millions. The accompanying Elevation 2001 Tour has sold out arenas throughout the world, and U2 have racked up a slew of honors. Suddenly, it’s as if they never stopped being the biggest band in the world.

“It’s hard for rock ‘n’ roll artists to grow and mature and find ways to have long careers,” says New York Times rock critic Ann Powers, an avowed fan of the band. “U2 figured out how to break out of that, and a lot of bands don’t.”

In the wake of “All That You Can’t Leave Behind,” Bono and U2 have been praised for coming back to the kind of guileless art-rock that originally gained the band acclaim before Ronald Reagan had even unpacked his bags in Washington. But like his band mates, Bono is not the same man he was 20 years ago. In U2′s first several albums, Bono’s lyrics exhibited uncommon faith in an era full of anger and gloom. But after the darker introspection of the band’s albums from the last decade, “All That You Can’t Leave Behind” is particularly notable because Bono has again come to see the glass as half-full.

Yet when he sings “It’s a beautiful day, don’t let it get away,” it’s not youthful pie-in-the-sky optimism, but a faith that’s been redeemed over time. That’s something altogether more meaningful. And while that was already true before Sept. 11, it’s even more relevant now. This is no time for idealism, but rather one in which defiant, profound hope is desperately needed. And that’s what “All That You Can’t Leave Behind” is all about.

As Bono has become a prominent spokesman for Third World debt relief and the related African AIDS epidemic, there’s no doubt it recalls countless pet causes of years past. In the mid-’80s, as “War” (1983) and “The Unforgettable Fire” (1984) first carried U2 toward multiplatinum success, they were fixtures in the Band Aid and Live Aid campaigns to end famine in Africa. When “The Joshua Tree” (1987) was about to make them the biggest rock band in the world, U2 joined Sting and Peter Gabriel belting out hits for Amnesty International. Around the same time Bono joined the chorus of artists singing “I ain’t gonna play Sun City,” in an effort to end South African apartheid. Because it’s easy to be cynical about high-profile celebrity causes, it’s to his credit that such a high-profile star managed to maintain credibility while so actively utilizing the spotlight, however nobly, for his own objectives.

Remember back in the late ’80s when Arizona dragged its feet establishing a Martin Luther King holiday? Soon after, a lot of famous acts (Stevie Wonder, the Doobie Brothers) canceled their concerts there. Not U2. Playing a sold-out arena in Tempe, they instead prepared a statement of protest for the crowd, played a rollicking show and afterward invested thousands of their own dollars in the grass-roots campaign against Gov. Evan Mecham, the MLK holiday’s chief opponent. “Who are they to tell Arizona what to do?” raged one of Mecham’s aides. And really, he was right. U2 should probably have canceled the show, which Bono later confessed to biographer Carter Alan. But, however clumsily they came off, or how much they exposed themselves to justifiable criticism, U2 were willing to risk themselves, to use music as ammunition in a larger struggle regardless of the consequences. How many corporate rockers can you say that about?

Yet compared to Bono’s meeting this summer with North Carolina Sen. Jesse Helms to discuss the African AIDS crisis, all that past activism seems like child’s play. In recent times he has brought his crusade to the likes of President Bill Clinton, British Prime Minister Tony Blair and Pope John Paul II, the last of whom famously donned the singer’s trademark shades in a surreal photo op. But Bono’s summit with Helms was much more noteworthy, because it marked a leap over the ideological divide.

For millions the North Carolina senator symbolizes American conservatism at its ugliest. And yet here was Bono breaking bread with Helms at the Capitol as if the two were old chums. “You’ll always be a friend here,” Helms told Bono that day.

“U2 has always been about bringing ideas to a larger audience, and crossing boundaries,” says Powers. “I think that Bono’s wise enough at this stage of his life to see that sometimes the right connection can come from a surprising place.”

Bono’s meeting with Helms reflects a rite of passage most of us experience sooner or later. Maybe his more idealistic days seemed a more appropriately romantic rock star stance, but Bono has learned that all the posturing in the world won’t make cohesive progress without cooperation across the political boundaries. Why wave protest signs outside when you can waltz through the corridors of power?

“He’s very articulate,” says Rolling Stone contributing editor Anthony DeCurtis, who has written about U2 frequently over the last 15 years. “In a great tradition of Irish rhetoric, Bono has a way of just leaping over contradictions, and through sheer eloquence and charm managing to bridge otherwise completely unbridgeable gaps.”

Whether it’s our friends or our idols, the people who capture our imagination are always changing. Bono has evolved over two decades from heart-on-his-sleeve idealist, to irony-ensconced rock ‘n’ roll Liberace, and finally to a sort of hopeful pragmatist. Regardless of the actual effectiveness of his crusades, his more practical political acumen is something Bono has been working toward — in and out of music — for most of his life.

What originally transported U2 from Dublin clubs to the world stage was a combination of punk rock aggression and a defiantly purposeful attitude. Mere months before U2′s band mates first met, the Sex Pistols’ Johnny Rotten famously sang that there was “no future for you.” Growing up just across the water in Ireland at a time of near-revolutionary civil strife, nobody could have blamed Bono for feeling the same kind of bitter angst.

As the child of a Catholic father and Protestant mother, however, Bono saw beyond the polarized religious rhetoric, his lyrics demanding a more promising future. As U2 gained notoriety in songs like “Sunday Bloody Sunday,” with Bono singing, “I can’t believe the news today, I can’t close my eyes and make it go away,” the band pleaded for peace with 11th-hour urgency. We loved them for it, even if deep down we knew it wouldn’t change the world.

Various strains of this idealistic persona remained all the way to the album and concert film “Rattle and Hum” (1988), but by that point in U2′s career something had to change. Whether it was their derivative rendering of American roots music, or how their overexposed politicking simply grew tiresome, by 1991′s “Achtung Baby,” a complete reinvention was not only advisable, but downright essential.

In the changed musical landscape of the post-Nirvana early ’90s, a lot of famous acts lost their way. But the masterly “Achtung Baby” suddenly made U2 more vital than ever. And after bristling for so long at the notion of rock ‘n’ roll stardom, their embrace of the crazy burlesque pageant that is rock was oddly refreshing. While U2′s stage persona took a turn toward the bombastic with the Zoo TV Tour in 1992, Bono largely took leave from high-profile social activism as his lyrics entered a sort of blue period, exploring the doubt and desperation we’ve all felt at times.

“For all of the theatrics of ‘Zoo TV’ and ‘Achtung Baby,’ there still is a core of belief in U2 that has remained constant,” notes DeCurtis. “There’s a kind of skepticism, or questioning side of them, that’s come to the surface, but also there’s a kind of yearning that real ironists never admit to.” Looking back with the hindsight of history, the darkness of “Achtung Baby” is precisely what gives the optimism in “All That You Can’t Leave Behind” its legitimacy.

Great artists also have an intrinsic sense of timing, and U2 are no different. Just as “Achtung Baby” perfectly reflected the irony-obsessed early-’90s zeitgeist, “All That You Can’t Leave Behind” embodies our renewed taste for the genuine, which has only increased following the events of Sept. 11. “It reminds me of that aphorism by William Blake: Enough or too much,” says DeCurtis. “That’s pretty much U2′s guiding principle. Whether it’s their total reinvention on ‘Achtung Baby’ after ‘Rattle and Hum’ or ‘All That You Can’t Leave Behind’s’ return to essentials, the connection is that they’ve always bounced back from something beyond its usefulness.”

And so a man who just a few short years ago was parading the concert stages of Europe dressed as MacPhisto, an absurd combination of Faust’s Mephistopheles and Liberace, can go on to share the stage with the most powerful men and women in the world. That Bono has so often looked absurd and bounced back gives every one of us who has embarrassed ourselves at a party, or pontificated far too long at a podium, or created art that disappointed, hope that the future is indeed unlimited. Bono reminds us that time makes everything possible.

Not only is that timing useful when it comes to making rock records, but it’s equally important in politics. That’s why we see Bono out there now with Jesse Helms and John Paul II. As the age of irony wanes, and the world unites against an uncannily elusive enemy, a rock star like Bono can speak matter-of-factly about social causes again and actually be taken seriously. Whether it’s in the studio or on the steps of the U.S. Capitol, Bono knows he’s got to ride the wave while it lasts.

If you’re looking for snark, go elsewhere. (OK, the bald eagle thing was kind of hokey.) I am officially over my Rick Warren tantrum (at least until I see him Tuesday); between Episcopal Bishop Eugene Robinson’s moving blessing to open the concert, to the San Francisco Gay Men’s Chorus singing “My Country Tis of Thee” where Marian Anderson sang it almost 70 years ago (after the Daughters of the American Revolution kept her out of Constitution Hall because she was black), followed shortly thereafter by the Navy Men’s Glee Club. Rick Warren, you can’t take that away from me. When the openly gay Robinson called on God to “bless us with anger — at discrimination, at home and abroad, against refugees and immigrants, women, people of color, gay, lesbian, bisexual and transgender people,” I knew we’re not in Dick Cheney’s America anymore.

If you’d told me that Garth Brooks would sing more songs than any other entertainer, including Beyoncé, Bono and Bruce Springsteen, I’d have been prepared to be disappointed. But for me one high point was Brooks doing the Isley Brothers’ “Shout” — it helps if you saw the movie “Wedding Crashers’” great montage showing lame cover bands doing “Shout” at weddings of every race and culture, Jewish, Indian, Irish, African-American. Yes, I’ll admit that made me think of Obama presiding over a sappy interracial wedding, and watching that sea of arms flying up every time Brooks said “throw your hands up” was one of my favorite moments of the day.

The genius of the whole event was the culture mashup — readings presented by duos like Steve Carell and Jamie Foxx, Jack Black and Rosario Dawson, Laura Linney and Martin Luther King III, Forest Whitaker and Ashley Judd — yes, Jack Black. Likewise, Jon Bon Jovi and Bettye LaVette’s duet on Sam Cooke’s Obama anthem “A Change Is Gonna Come” was extraordinarily moving. My personal high point — I’d have braved the cold and crowds for this moment alone — was Pete Seeger and his grandson, joined by Springsteen, singing all the lyrics to “This Land Is Your Land” — and watching Obama sing along. The only remotely controversial note (beyond Robinson’s prayer for anger at discrimination) was when Bono called the values embodied in Obama’s election “an American dream, an Irish dream … a European dream, an African dream, an Israeli dream,” and then added: “And also a Palestinian dream.”

Obama himself called the celebration an expression of “just what it is that we love about America.” And where I was disappointed that Obama only slightly nodded to Dr. Martin Luther King Jr. in his Denver acceptance speech (on the 45th anniversary of King’s “I have a dream” speech), today his praise and attention to the parallels of their cause was full-throated and moving. Obama’s voice deepened and grew louder as he talked about King’s dream “that his children might be judged on the content of their character.” He also praised “the man who made this day possible,” Abraham Lincoln, and said American progress will come “if we could just recognize ourselves in one another.”

And yes, then there was Garth Brooks. The entire crowd — young, old, black, white, Latino, Asian, everyone — seemed to sing along to “American Pie,” including Obama, which could mark him, generationally and culturally, more than anything else that happened today. Who knew they knew all the words? I didn’t until today (actually, Brooks wisely shortened it). And I couldn’t help seeing Brooks, singing along with a multiracial youth choir, as another part of Obama’s outreach to red America, a real reminder that he doesn’t plan to be president of blue America, or red America, but the United States of America. I hope Republicans get the message.

I think this will go down as one of the best days of my life for a long time, except for the fact that I had to make a kind of comic “Sophie’s Choice”: I had a press credential and my college-student daughter didn’t, so she headed for steerage when I got to the press tent. I told her I’d probably just come out and join her in the crowd, how could I see it without her — until I saw that the press area had uniquely awesome views (they don’t always) and I couldn’t imagine leaving. We texted throughout, and she shared her great stories of the real event — topped by people climbing on Porta-Potties to get a better view, then being ordered down by police, then being unable to get down, then being rescued by men in camoflauge. I missed her when Pete Seeger sang “This Land Is Your Land,” because I used to sing it to her 19 years ago, when she was a baby.

It was the kind of event that made you want to share TMI personal details like that — and also the kind of event where you didn’t need to know a soul to suddenly be surrounded by friends and family. Nora and I met up afterward for the long trek home, and we felt lucky to have two sets of views of this historic day. For the first time in my adult life, to paraphrase Michelle Obama, I am crazy in love with my country, and it was fun to attend this schmaltzy sort of wedding to celebrate the change that’s gonna come. I reserve the right to update this post later, when I slap my forehead and say, “How could I not have written about that?” Or maybe I’ll just Tweet it.

The next question, about his asterisk-level standing in the polls and his anemic fundraising, may have prompted Biden to wonder why he had lingered. But rather than decry the horse-race surveys or make excuses for the paltry $2.4 million he collected in the second quarter (sixth place in the Democratic money marathon), the six-term Delaware senator made his anything-can-happen argument with the aid of a potent audience-participation experiment.

Biden simply asked, “How many of you think that the majority of the people in Iowa have firmly made up their mind about how they will vote in the caucuses?” Not a single hand was raised, demonstrating that most Iowans recognize how shallow are the sentiments reflected in the polls.

First elected to the Senate in 1972 at age 29 (three weeks before he was constitutionally eligible to serve), Biden has always seen himself as a smart, hardworking, glad-handing East Coast politician with a gift for Irish blarney and charm. When he made an abortive bid for president in 1987, Biden now admits, “I was focused on my conviction that I was a better candidate than the other people — and not that I was ready to lead the country.”

But as the chairman of the Senate Foreign Relations Committee, Biden is now in the curious position of running for president as the long-shot candidate with substance, while Barack Obama, John Edwards (some days) and Hillary Clinton (by marriage) outshine him in the megawatt, star-search spotlight. The self-made senator, who graduated from the University of Delaware with a C average, can only triumph if experience ends up mattering more than excitement. As Biden explained in his stump speech in Grinnell, simultaneously sounding boastful and aw-shucks embarrassed, “I know most every one of these world leaders by their first name. It’s not because I’m important … I was a kid coming up when they were coming up.”

From his perch at the Senate Foreign Relations Committee, or possibly as a Democratic secretary of state (his likely job had John Kerry been elected) or as president, Biden may yet play a central role as America grapples with the never-ending nightmare that is Iraq. Biden, along with his fellow Sens. Clinton, Edwards and Chris Dodd, voted for the 2002 resolution permitting Bush to launch the war. During a 2005 interview with me, Biden recanted his vote, saying, “I never figured on the absolute incompetence of the administration … If I knew Cheney and Rumsfeld so wholly possessed the president’s attention, I never would have voted for that.”

Unlike his rivals for the nomination, Biden has been championing a plan (which he proposed last year with Leslie Gelb, the former president of the Council on Foreign Relations) to subdivide Iraq along ethnic lines within a federal system. (The plan for separate Sunni, Shiite and Kurdish regions is explained in detail on Biden’s campaign Web site.)

But these days, Biden acknowledges that it may soon be too late to salvage anything from the debacle in Iraq. During an interview Tuesday along the Iowa campaign trail, Biden talked bluntly between stops about the dire alternatives facing the man he imagines will be the next president: “I may be left on Jan. 20, 2009, with no option but to withdraw and to contain [the civil war within Iraq]. To literally have inherited a fractured country … where there is no way to put Humpty-Dumpty back together.”

During one conversation in the campaign van headed into Grinnell, Biden found himself torn between holding a cup of coffee and gesturing with both hands. Confronted with a classic unwinnable situation, he carefully put the coffee cup on the floor. There is a bluntness to Biden, which stands in contrast to a candidate like Clinton, who seems to mentally convene a focus group before answering a question.

But Biden can also be impolitic in his criticisms of immediate-withdrawal-for-Iraq political grandstanding, and the bloggers who encourage it. “I don’t believe that this sort of red-meat, ‘I’ll get out quicker than the other guy’ [competition] has resonance,” he said, adding that in political terms for the Democrats, “I think it has a real danger.” Biden, who has endured 22 years of Republican presidents while in the Senate, criticized bloggers’ vow to “take back” the party. “They don’t own the Democratic Party. What are they talking about?”

No antiwar stance arouses Biden’s ire like Bill Richardson’s hyperbolic claim that he alone of the major Democratic presidential contenders would leave no residual forces in Iraq. As Biden put it, “Governor Richardson, God love him, says that he is the only one who is going to get out entirely, but he is going to leave enough forces to protect our embassy. He ought to talk to the Marines; they say that’s 10,000 troops.”

There is a free-form quality to Biden’s stump speeches as arguments appear from nowhere, presumably because something occurred to the candidate, and then disappear from the repertoire for the rest of the day. Tuesday morning in Cedar Rapids talking to 100 Democrats (a good-size crowd for Iowa in the days before Obama mania and two Clintons campaigning together) at the Blue Strawberry Coffee Co., Biden battled the roar of the espresso machine as he tried to explain a controversial recent vote in the Senate.

Alone among the Democratic presidential contenders, Biden voted for Iraq war appropriations, even though the final legislation did not contain a timetable for withdrawal. Alluding to that vote, he said, “If there is a single solitary troop left in Iraq, we must protect that troop. We have a moral obligation to protect these kids we send … We need 67 votes to overcome the president’s veto. We can cast all the symbolic votes we want. But the bottom line is that I’m not trading symbolism for lives.”

As a presidential candidate, Biden lives in a world seemingly free from fear about how his words will appear out of context. Back in January, as he was launching his presidential campaign, Biden stumbled badly in an interview in which he described Obama as “clean” and “articulate.”

But even now, Biden cannot resist flirting with rhetorical danger. In Cedar Rapids, he borrowed a catchphrase from an anti-integration 1968 third-party candidate while discussing the healthcare plans of his rivals: “As old George Wallace used to say 40 years ago, ‘There ain’t a dime’s worth of difference between our plans.’” Two minutes later, talking about an idea for African debt relief that he had suggested to Bono, Biden said humbly, “It’s not Al Gore inventing the Internet.”

That one even registered on Biden’s internal danger meter, as he realized that there are worse political dangers than appearing immodest. Walking over to me, the only national political reporter in view, Biden loudly insisted, to the delight of the crowd, “It’s real, real clear that I didn’t say that.”

Moments like this, Biden conceded in our interview, represent the downside “of my being straightforward and candid … I’m going to get myself into trouble.” Then Biden, who was already in the Senate as Obama was just getting ready for middle school, said, “I can’t start to calibrate all this stuff … The public in the primaries, as well as the general election, are going to judge me for all of who I am.”

And for Joe Biden — the candidate who never stops talking, but often has much to say — the inherent contradiction is between his still youthful irreverence and the hard-won gravity that comes with the chairmanship of the Senate Foreign Relations Committee and watching America go so tragically awry abroad.

It’s awfully tempting to look at this media play and start cracking jokes about how Forbes magazine is going to go all-out on a campaign for debt relief for Africa and increased foreign aid for HIV prevention. That would be something of an editorial revolution, since Steve Forbes, the publisher, is on record as critiquing Bono’s approach to helping out the world’s poor and sick. As he wrote in his column just a few months ago:

Bono’s “emphasis on giving more money to benighted countries is misbegotten. Most of it will be wasted, and despite ‘safeguards’ all too much of it will be siphoned off by corrupt politicos and bureaucrats. Africa has received more than $400 billion in aid since 1960, yet per capita income has declined. No other area of the world has suffered such a regression. Blair, Bono et al. should be focusing on measures that would allow sub-Saharan Africa’s existing entrepreneurial energies to put their countries on the path of rapid, India-China-Pacific-Rim-like economic growth. There are huge barriers blocking those who could catapult Africa’s poor nations onto an economic fast track.”

Don’t bet the house on Mr. “Capitalist Tool” Forbes changing his tune. This purchase of a stake in Forbes Media by Elevation, the investment group of which Bono is a member, doesn’t seem to be a question of editorial philosophy — Elevation seems far more enchanted by the millions of visitors that the Forbes Web site attracts every day.

But still, it’s not often that you get handed a plate of irony as tasty as this one. Bono wrote the introduction to development economist Jeffrey Sachs’ “End of Poverty,” which calls for precisely the kind of massive foreign-aid increases and direct government interventions that are so antithetical to Forbesian ideology. And while on the one hand it is puerile to think that privatization and deregulation can turn Somalia or Rwanda into China or India, it’s also quite true that past decades are littered with failed attempts to use aid money to help Africans escape their poverty trap.

Maybe the real significance of the Bono-Forbes connection is that just the fact that Bono is even tangentially involved is an excuse to revisit the challenges faced by sub-Saharan Africa once again. Underpinning the efforts of Sachs and Bono is a fundamentally optimistic mindset — yes, they concede, many previous efforts have failed. But smart people learn from their mistakes, and if we keep trying, we can figure out ways to improve public welfare in previously “benighted” countries. As Forbes magazine once reported, Bono’s efforts in recent years were instrumental in pointing out the utterly cockeyed nuttiness that African nations owed more to the developed world in annual debt repayments than they were receiving in foreign aid. That’s clearly a “huge barrier” to development, and it’s not one that further deregulation would do a darn thing to address.

Wolfowitz spokesman Kevin Kellems said Wolfowitz and Bono “clicked.” “They were very enthusiastic, detailed and lengthy conversations,” Kellems said. He said that the conversations “were incredibly substantive about reducing poverty, about development, about the opportunity to help people that the World Bank presidency provides and about charitable giving and social progress around the globe.”

The word from the Bono side of the conversation was a little less effusive. The government relations director for Debt, AIDS, Trade and Africa, a lobbying group Bono helped to found, told Reuters: “Bono thought it was important that he put forward the issues that are critical to the World Bank, like debt cancellation, aid effectiveness and a real focus on poverty reduction.”