The important point to remember here, as Alex Seitz-Wald explained yesterday, is that there really isn’t much of an ideological divide in this race. Dewhurst, who has served as Rick Perry’s lieutenant governor since 2002, would be a very conservative vote in the Senate – to the right of Hutchison and John Cornyn, the state’s other Republican senator. But Dewhurst’s establishment support and his fixture status in state politics (he’s been in statewide office for 14 years) aren’t the best match for the GOP’s Tea Party-era base, and this has created an opening for Cruz to run as the “pure” alternative.

For understandable reasons, Cruz has tried to portray this as a showdown between the party’s conservative and moderate wings. But those kinds of fights are relics of a different time. Today’s GOP, especially at the national level, is a cohesively conservative party, one that has moved ever farther to the right in the three decades since Ronald Reagan’s 1980 victory.

The Tea Party movement isn’t about purging moderates; that happened a long time ago. It’s about forcing the entire GOP to embrace a partisan warfare style of governance. When it comes to the Senate and House, that means electing candidates who will shun compromise with Democrats and exploit every possible legislative tool to advance their own agenda and stall the other party’s. It is about absolutism.

As Richard Mourdock, who knocked off Richard Lugar in Indiana’s GOP Senate primary earlier this month, put it, “”My idea of bipartisanship, frankly, going forward is to make sure we have such a Republican majority in the U.S. House, in the U.S. Senate and in the White House that if there is going to be bipartisanship, it’s going to be Democrats coming our way instead of them trying to pull Republicans their way.”

Mourdock was the first high-profile Tea Party primary winner of the 2012 primary season, and his triumph was followed a week later by the surprise victory of Deb Fischer in Nebraska. Now comes Cruz’s strong performance, and the potential for an outright victory in the runoff. There are other possibilities still on the board too, like in Wisconsin, where former Gov. Tommy Thompson could have a lot of difficulty in the August 14 GOP Senate primary. And all of this, of course, comes on the heels of 2010, when several Republican establishment heavyweights went down in primaries (or, in one case, a state convention).

In some cases, these Tea Party primary wins can have real general election consequences. In ’10, Republicans would have won Senate races in Nevada and Delaware (and probably Colorado, too) if they hadn’t nominated candidates with fringe credentials and erratic tendencies. This year, Mourdock’s win has put the Lugar seat in play for Democrats, while Fischer’s Nebraska victory was exactly what Bob Kerrey, the Democratic nominee was hoping for (even if Fischer remains the clear favorite there). In the case of Texas, though, the Dewhurst-Cruz runoff outcome won’t matter for November. Republicans will hold the seat either way.

To find the real impact of a primary like last night’s, you’d probably have to get into the heads of the current Republican members of the U.S. Senate, especially those who will be up for reelection in 2014. They can see that the revolt of ’10 hasn’t died down – that the party base is just as hungry for “purity” and offended by insider-ness as it was two years ago. The more they modify their behavior to conform to this, the less productive the Senate will be. And, as you’ve probably noticed, it isn’t all that productive to start with.

Not long after that, Donald Trump used an interview to restate his long, long-ago debunked claim that Obama was born in Kenya.

“That’s what he told the literary agent,” he told the Daily Beast. “That’s the way life works… He didn’t know he was running for president, so he told the truth. The literary agent wrote down what he said… He said he was born in Kenya and raised in Indonesia… Now they’re saying it was a mistake. Just like his Kenyan grandmother said he was born in Kenya, and she pointed down the road to the hospital, and after people started screaming at her she said, ‘Oh, I mean Hawaii.’ Give me a break.”

Trump is a prominent Romney supporter and is scheduled to appear with the candidate in Las Vegas today. But when reporters on Romney’s campaign plane offered Romney the chance last night to distance himself from Trump’s lunacy, he demurred.

“You know,” he said, “I don’t agree with all the people who support me, and my guess is they don’t all agree with everything I believe in. But I need to get 50.1 percent or more, and I’m appreciative to have the help of a lot of good people.”

It’s a weak excuse, obviously, since the same concern didn’t stop him from lashing out at the proposed Wright ad. The question is why Romney is so nervous about raining on Trump’s birther parade.

There are two basic theories here, and they probably overlap somewhat. One has to do with Romney’s relationship with the Republican Party base, where birther sentiment and sympathy for Trump can both be found in high concentration. It may be that Romney has decided that confronting those feelings could further arouse suspicions among conservatives that he’s a secret moderate who will sell them out as president.

The other theory has to do with Trump and his massive media profile. When he sounds off on current events, his reach extends far beyond the world of cable news and political blogs. He’s a genuine national celebrity, one who delights in using his platform to abuse anyone who’s crossed him personally.

Right now, Trump’s ire is focused on Obama, but he’s shown that he’s ready to open fire on Republicans who challenge his birtherism. Just look at his war of words with George Will that’s now playing out. Maybe Romney figures it’s easier to bite his tongue and take some heat from the media than to endure six months of Trump calling him names on every television program in America.

Either way, the Romney camp is looking at this situation too narrowly.

Let’s say that Romney were to come out and make a clear and emphatic break with Trump – calling birtherism invalid, stating that it has no role in the campaign, and reiterating his intent to wage a campaign about the issues (and, of course, Obama’s “failed leadership”). Realistically, what would happen?

Well, it would be a huge story, of course, with Trump probably throwing a hissy-fit. But so what? Republican leaders would stand with Romney, and the voices decrying him (besides Trump’s) would be relegated to the fringes. Maybe some rank-and-file conservatives would turn on Romney because of it, but ultimately it’s Obama-phobia that animates the GOP base. Meanwhile, the media would offer Romney glowing coverage for standing up to Trump, who – by the way – isn’t actually that popular with the masses. For once, Romney would come across as strong and principled. The image boost with swing voters would probably be significant, dwarfing whatever intraparty damage he’d suffer.

It was almost exactly 20 years ago that Bill Clinton staged his “Sister Souljah moment,” using a speech at Jesse Jackson’s Rainbow Coalition to decry a black rapper who had been quoted in the wake of the L.A. riots as saying that blacks had a reason to kill whites. This supposedly was a key part of Clinton’s successful bid to sell himself as a new Democrat, one who was unbeholden to and unafraid of his party’s base.

Trump’s bloviating is an opportunity for Romney to do the same thing – but he and his campaign are apparently blind to it.

The problem for Obama: This isn’t translating into much of an overall lead. In the ABC/WaPo poll, he’s clinging to a 3-point edge, 49 to 46 percent, while the Real Clear Politics average of all polls puts his lead at just under 2 points. There are a lot of voters, in other words, who see Romney pretty much as the Obama campaign wants them to see him but who are still willing to support him anyway.

This speaks to the challenge of running for reelection against a backdrop of pervasive economic anxiety. It gives swing voters a strong incentive to vote the incumbent out, and tends to lower the bar in terms of what they’re willing to accept in a challenger candidate. The ABC/WaPo numbers offer a glimpse of this phenomenon at work.

When it comes to making the race competitive, the key for Romney seems to be a specific type of voter: white, middle-/working-class, and economically struggling. The poll finds that these voters agree with the idea that Romney will better serve the interests of the rich and financial institutions, but that they also see him as better for the middle class. According to the Post’s write-up:

Among white voters trying to stay in the middle class, Romney is considered the better candidate for that group by a 20-point margin; Obama is preferred by better than 3 to 1 among middle-class nonwhite voters, regardless of their sense of security.

This dovetails with earlier polling that showed Obama’s support from non-college-educated white voters – which was never that strong to begin with – plunging to new lows, particularly with men. Several theories have been proposed to explain this, including the idea that it reflects the culture-based attacks and insinuations that have been a staple of the right’s opposition to Obama. There may be something to that, but according to ABC/WaPo nearly three-quarters of whites who say they’re struggling lack college degrees, so they’re sympathy to Romney might simply reflect their own economic anxiety, and their instinct to punish whoever’s running the country for it.

That’s precisely the instinct that Romney’s message is designed to stoke. His economic pitch is in many ways contradictory and incoherent, but that’s intentional. Romney isn’t trying to sell Americans on some detailed, comprehensive plan to rebuild the economy. His goal is to offer broad, pleasant-sounding policy prescriptions while playing up dire statistics and anecdotes about the economy and the deficit. When you really boil it down, as I’ve written before, the Romney message is simply this: If you’re feeling anxious about the economy, don’t ask questions – just vote out the guy in charge. The ABC/WaPo numbers are an indicator of the potential effectiveness of that strategy.

The Cherokee story, according to the survey, has definitely dented the public’s consciousness; 72 percent of voters say they’re aware of it. But by a 49 to 28 percent margin, they also say that Warren is telling the truth about it, and by a 45 to 41 percent margin they say she didn’t benefit professionally from listing herself as Native American back in the 1990s.

“I’m not saying there was no damage from the Native American thing, but if you zoom out to see what the net effect was, it was minimal,” David Paleologos, who conducted the poll, told the Boston Globe. “It’s considered a nonstory.”

There are hints of the story taking a toll on Warren’s image. Her unfavorable score is up 5 points from the last Suffolk poll in February, from 28 to 33 percent, while her favorable score sits at 43. Brown, by contrast, has a more robust 56 to 28 percent favorable rating. In that February poll, Brown enjoyed a 9-point lead over Warren, 49 to 40 percent, but that result was dismissed by both sides as an outlier – not that it’s stopping Democrats now from crowing that Warren is surging.

Really, though, the poll just shows that the race is back to being the nail-biter everyone’s long assumed it would be. If the outcome was based strictly on personal popularity, Brown would win easily. But the Republican label is a profound liability in Massachusetts, especially for candidates for federal office. This is why the Suffolk poll also finds Brown failing to break 50 percent against Maria DeFranco, Warren’s little-known Democratic primary opponent. (In a head-to-head race with Warren, DeFranco trails 71 to 6 percent.)

Warren’s challenge isn’t to become better-liked than Brown; it’s to make herself likable and acceptable enough for voters who are fond of and identify with Brown but don’t want to send a Republican vote to the Senate. On this front, there are some encouraging signs for her in the poll. She beats Brown 49 to 36 percent on the question of who will better represent middle-class families and 40-37 percent on who is more honest. And she’s not far behind him (47-42) on who’s more independent – a trait Brown has tried to make his calling card.

In Arkansas, the other state to hold its primary yesterday, the results were only slightly less humbling to Obama, who defeated an actual human-being candidate — a Tennessee lawyer named John Wolfe — by a 58.4 to 41.6 percent spread, with more than a third of the state’s 75 counties siding with the challenger. Wolfe, if anyone asked him, was running against Obama from the left, on a progressive economic message. But to the average Arkansas voter, his name might just as well have been “not Obama”; he had no money, no campaign organization, and no name recognition, and he received scant media coverage.

Whether this qualifies as Obama’s most humbling primary night of 2012 is open to debate. Just two weeks ago, a federal inmate who somehow maneuvered his way onto the West Virginia ballot racked up nearly 41 percent against the president in that state’s primary and carried 10 counties. Back in March, Obama was held to 57 percent in Oklahoma, losing 15 counties to anti-abortion zealot Randall Terry and another gadfly candidate. Terry actually qualified for delegates in that contest, prompting national Democrats to invoke their “LaRouche rule” and deem him unqualified to actually receive delegates.

There were also problems for the president in pockets of Louisiana, where Wolfe cleared the 15 percent delegate eligibility threshold in several congressional districts. Democrats are refusing to actually allocate any delegates to him, though, on the grounds that he failed to file a comprehensive delegate selection plan – a rationale that is also being invoked in Arkansas. Wolfe is vowing to overturn the rulings in court.

In terms of deciding the Democratic nomination, obviously, none of this really matters. Obama has won most states by the massive margins that incumbent presidents typically rack up against fringe challengers and “uncommitted,” and he long ago surpassed the magic number of delegates needed for re-nomination. In most of America, this year’s Democratic primaries have been just as uneventful and unremarkable as they were in 1996, the last time a Democratic incumbent sought reelection.

But then there’s that sea of resistance in Appalachia and states like Arkansas and Oklahoma. A case can be made that Obama’s energy policies contributed to his West Virginia headache, but otherwise there’s no sense trying to pin this on anything he’s actually done as president because the resistance was just as apparent when he ran four years ago.

Back then, Obama was crushed by Hillary Clinton in West Virginia by 41 points – even though it was clear by primary day that he was on his way to being the nominee. In Kentucky, Clinton’s margin was 35 points. In Arkansas (where she served as first lady for more than a decade), it was 44. And in Oklahoma, it was 25. The same largely poor, rural and white areas that gave Clinton her best numbers in 2008 are now doing the same for John Wolfe, “uncommitted” and Randall Terry. The problem was just as apparent for Obama in the fall of 2008, when he improved on John Kerry’s 2004 performance in just about every corner of the country except the Oklahoma-to-West-Virginia swath.

Chalking this up only to race may be an oversimplification, although there was exit poll data in 2008 that indicated it was an explicit factor for a sizable chunk of voters. Perhaps Obama’s race is one of several markers (along with his name, his background, the never-ending Muslim rumors, and his status as the “liberal” candidate in 2008) that low-income white rural voters use to associate him with a national Democratic Party that they believe has been overrun by affluent liberals, feminists, minorities, secularists and gays – people and groups whose interests are being serviced at the expense of their own.

The good news for Obama is that this probably doesn’t say much about what will happen in November. The damage is limited to states he was already expecting to lose to Mitt Romney. Not that this will stop Republicans from playing up Kentucky and Arkansas as the latest proof of Obama’s shattered popularity. But that’s just spin. He could have a 60 percent approval rating, and he’d still be getting embarrassed in these states.