But is a Trump endorsement a good thing for Romney? That’s a more complicated matter, and it gets to the basic tension between Romney’s primary and general election imperatives.

From a general election standpoint, it’s potentially problematic. For one thing, Trump has always been a lightning rod, but in the past year he’s emerged as a particularly divisive figure, thanks to his birther crusade and degrading attacks on Obama. To the extent these antics have resonance, it’s on the right; among swing voters, they’re much more likely to be a turnoff. At the height of his political activity last year, Trump’s unfavorable score with all voters soared to new heights, and it remains at 48 percent today — eight points above his favorable number.

Plus, Trump’s own top 1 percent image could help reinforce Romney’s main vulnerability as a general election candidate. With his Bain Capital history and personal tax status dominating the news for the past month, Romney’s standing has plunged with blue-collar swing voters, a constituency that will be critical to the GOP’s hopes of ousting Obama. Nor has Romney helped himself with his often-clumsy efforts to inoculate himself against the charge that he’s an out-of-touch plutocrat. Does he really want to be associated with a celebrity business tycoon whose catchphrase is “You’re fired”? Already, Democrats are having some fun with this. “They both like firing people,” DNC chairwoman Debbie Wasserman  Schultz said on MSNBC. “They both make millions doing it.”

So you might think this would be a good moment for Romney to stage a Sister Souljah moment — to dramatically refuse Trump’s endorsement, bask in the resulting praise from the media, and reassure swing voters that he doesn’t embody all of the excesses of Tea Party-era Republicanism. But according to ABC News, Romney’s campaign has had “multiple discussions” with Trump in an effort to secure an endorsement.

From a primary season standpoint, this does make sense. Romney is likely to win the GOP nomination, but Gingrich (and Rick Santorum, for that matter) is still out there and the possibility of more embarrassing hiccups is very real. For instance, Gingrich could plausibly win a bunch of Southern states in early March, a result that would revive all of the talk about Romney’s weakness as a candidate and potentially extend the GOP race through the spring and into the summer. So Romney isn’t out of the woods yet, and it would be risky to make an enemy out of Trump right now. After all, Trump’s anti-Obama shtick resonates with many of the same hardcore Republicans who gravitate toward Sarah Palin, Rush Limbaugh, Herman Cain and the other prominent Tea Party voices who have been helpful to Gingrich recently.

In other words, Romney may well recognize Trump’s potential to hurt him with general election voters. But he wants to make sure he gets to the general election, and that means playing along

Update: And now it’s official. In a somewhat bizarre scene just before 1 p.m. PST, Romney stood next to Trump and formally received his endorsement. “Mitt is tough,” Trump said. “He’s sharp. Governor Romney, go out and get them — you can do it!” Romney seemed slightly uncomfortable, praising Trump for his supposed knowledge of economic issues and his anti-China rhetoric (and even calling him “Mr. Trump”), then veering into his customary talking points. “There are some things you can’t imagine happening in your life,” he remarked at one point. “This is one of them.” What he meant by this wasn’t exactly clear, but his tone suggested he didn’t mean it in the “Wow, this is the greatest thing that’s ever happened to me!” way. Romney didn’t take questions from the press.

This is what made Santorum’s initial pledge not to make social issues the focus of his Michigan campaign a serious problem for Romney. Conservatives who vote on cultural issues already didn’t trust Romney and already knew that Santorum was one of their own. So by playing up his economic message (and his own middle-class identity), Santorum would have a chance to make Romney’s problem with blue-collar and middle-class voters worse while expanding his own base and showing party leaders that he’s more than a niche candidate and that they needn’t fear nominating him.

Instead, just about every headline that Santorum has generated since then has been about culture war politics, a trend that has accelerated in the past few days as he’s blasted Barack Obama’s “phony theology,” railed against mandatory coverage of prenatal care, and even made a Hitler reference. There’s also the stir that one of his aides caused on Monday by warning on national television about Obama’s “radical Islamic policies.” (She meant to say “environmental policies,” the aide claimed.) And these are just the highlights.

I previously theorized that Santorum might be doing this because he’s worried about anti-Romney evangelical voters — particularly in the South — voting for Newt Gingrich, whose candidacy was just tossed another lifeline by Sheldon Adelson, and splitting the conservative base. Or maybe he’s just doing it because he’s Rick Santorum and he can’t help himself. Whatever the explanation, his refusal to rein himself in after his “phony theology” remarks first attracted notice is drowning out whatever he has to say about economic issues and reinforcing his image as a culture warrior politician.

This poses two problems for him. One is that the negative tone of the headlines he’s generating — at one point Monday, the top of the Drudge Report was monopolized by links about Santorum controversies — could be alarming to Republican voters in Michigan (and Arizona, for that matter) who aren’t part of the hardcore base. That is to say, conservative voters who have their doubts about Romney and are receptive to an alternative might now conclude that Santorum is no more credible than Gingrich, Perry or Cain. There are now clear signs that his lead over Romney in Michigan is vanishing. Romney’s heavy television presence in the state probably explains most of this, but Santorum’s antics threaten to exacerbate the trend.

The bigger problem has to do with the GOP’s opinion-shaping elites — elected officials, party leaders, activists, commentators, media personalities whose views tend to trickle down to the rank-and-file. An unusually high number of elites have remained on the sidelines so far. Since grabbing the spotlight two weeks ago, Santorum has essentially been auditioning for them. If he can show them he’s for real, their support would radically enhance his prospects of winning the nomination, amplifying his own message, giving him invaluable cover against Romney attacks, and funneling serious money into his campaign (and a super PAC). But so far, he’s won very few new converts; Mike DeWine, the former Ohio senator and current attorney general, is the highest-profile endorsement Santorum has snagged.

So for now, at least, Santorum is virtually alone as he confronts Romney’s money and attacks — and now a days-long media firestorm over his own comments. It’s not a myth that there was, and is, an opening to Romney’s right. But Santorum may learn that even in the GOP of 2012, there’s such a thing as too much red meat.

Since the Florida primary, Adelson has been sending signals that he understands Gingrich is very unlikely to win the Republican nomination, that he is perfectly comfortable with Romney being the nominee, and that he doesn’t want to hurt Romney’s long-term prospects of beating President Obama.

There are also signs that Adelson, whose political involvement stems mainly from his hawkish views on Israel and the Middle East, isn’t enthusiastic about the man who has supplanted Gingrich as Romney’s chief GOP foe, Rick Santorum. As the Wall Street Journal reported earlier this week:

Mr. Adelson doesn’t oppose Mr. Santorum, but he doesn’t share the former Pennsylvania senator’s socially conservative positions, including his strong antiabortion views, associates said. Mr. Santorum was one of only two Republicans who didn’t meet with Mr. Adelson in October around the time of a candidates’ debate in Las Vegas, according to a person familiar with the matter.

Viewed in this light, Adelson’s new $10 million gift could be seen as an indirect contribution to Romney. After all, Gingrich seems to run best among religious conservatives in South, where several states will vote in early and mid-March. Santorum, who has already demonstrated strength in the Midwest, badly needs to fold those southern voters into his campaign if he’s going to have a real shot at knocking off Romney. A revived, or partially revived, Gingrich could severely complicate this task.

By the same token, a revived Gingrich probably wouldn’t be much of a threat to Romney, who has had little trouble beating back the former speaker during his two previous surges. Gingrich, with all of his personal and ethical baggage and with all his influential enemies within the Republican Party, is a much easier target than Santorum for the Romney campaign.

The ideal scenario for Romney would be for Gingrich and Santorum to be equally viable in the upcoming contests, splitting up the conservative vote and allowing Romney an easy path to victory. But if he has to have one main conservative foe, he’ll be much better off if it’s Gingrich. To the extent Adelson’s $10 million makes either of these scenarios more likely, it’s a huge boost for Romney.

What may be most interesting here is the apparent ideological gulf between Gingrich’s actual voters and his chief financial backer. Gingrich has been pitching himself as the candidate for conservatives who want a true believer and who see Romney as the embodiment of a Republican establishment that doesn’t really share their values. But it turns out that the guy keeping the Gingrich campaign alive is precisely the kind of Republican they suspect Romney is.

Assuming the reports are true, that’s a transparently lame excuse. Even if Romney has other events planned for the same night, he has two weeks to shuffle his schedule around. Besides, the GOP debates have been must-see events that have attracted massive audiences; the entire political world essentially shuts down when they take place. What could Romney possibly have scheduled that would keep him from attending?

Clearly, this is about Romney not wanting to take part — which, in and of itself, is hardly surprising. Debates can be tense and unpredictable and Romney comes to all of them with a target on his back. And in Rick Santorum, he now faces a main rival who is actually pretty good at them. Santorum knows exactly where Romney’s weaknesses are and exactly how to attack him. This is a threat that Romney didn’t have to worry much about with Rick Perry (who struggled to formulate complete thoughts on his feet), Herman Cain (who literally had nothing to say besides “9-9-9″) and Newt Gingrich, who melted down when Romney turned up the heat in two Florida debates last month. So from Romney’s standpoint, it would be ideal not to have to worry about any debate slip-ups and to focus on using his huge financial advantage to destroy Santorum with negative ads.

The problem is that skipping debates is something that confident, inevitable front-runners do — not front-runners who are so wounded that they might not even be front-runners anymore. With his poll numbers crashing and Santorum surging, Romney’s debate boycott looks awful, a reeling candidate who’s afraid to face his opponents. And it plays right into Santorum’s efforts to paint Romney as a candidate who has nothing to offer besides a deep bankroll and negative ads. This gives Santorum a valuable talking point for the days ahead — one that will become even more potent if he’s able to knock off Romney in Michigan on Feb. 28.

The funny thing is that Romney is actually pretty good at debates. Yes, he’s had a few slip-ups and he’s benefited from feeble opposition, but chances are he’d do just fine on March 1 — just as he’ll probably survive next week’s debate in Arizona, assuming he doesn’t back out of that too. In other words, he may get more grief now for skipping a debate than he’d get from his opponents if he actually showed up at it.

Update: Romney’s campaign has now confirmed that he won’t be at the March 1 debate:

“Gov. Romney will be spending a lot of time campaigning in Georgia and Ohio ahead of Super Tuesday,” spokeswoman Andrea Saul said in a statement. “With eight other states voting on March 6, we will be campaigning in other parts of the country and unable to schedule the CNN Georgia debate. We have participated in 20 debates, including eight from CNN.”

And now there’s a possibility that something similar could play out in the near future, this time thanks to the ineptitude of the Maine Republican Party.

The state GOP had given local communities a one-week window from Feb. 4-11 to hold caucuses, with the statewide tally announced last Saturday night. At that point, Romney was declared the winner by 194 votes (or a 3 percent margin) over Ron Paul. But there was a catch. Several communities had flouted the state party’s edict and held or scheduled caucuses outside of the designated window, while one county — Washington — had been forced by threats of inclement weather to postpone caucuses that were originally scheduled for Feb. 11 by a week.

At first, this didn’t seem like too big of a problem. Not counting votes from places that willfully ignored the window seemed reasonable enough; if they’d wanted to be part of the statewide tally, they could have followed the rules. And while Washington County did attempt to follow the rules, it seemed unlikely that the results from caucuses there would, when they were finally announced, alter the statewide outcome, given how low turnout in the county was for the ’08 caucuses and how poorly Paul did back then (eight votes).

But since last Saturday, some major errors in the state GOP’s official tally have come to light. As the Bangor Daily News reported this week:

However, a review of the town-by-town results released Saturday by the Maine GOP suggests that some communities that had caucused prior to Feb. 11 were not counted. Nearly all Waldo County towns held caucuses on Feb. 4 but those towns were blank in the results released by the state party. Additionally, Waterville held its caucuses ahead of time but were not included in the results.

Waldo County GOP Chairman Raymond St. Onge said the results were sent to the state party on Tuesday, Feb. 7. He said those results probably would not have changed the outcome but was disheartened the votes were not included.

St. Onge said he spoke to party officials late Tuesday about why Waldo County’s results were omitted.

“They said it was a clerical error,” St. Onge said. “I’m going to believe them because there were other errors that occurred. I don’t think it was intentional because our results wouldn’t have changed the winner.”

While St. Onge, the Waldo County chairman, says the omitted results wouldn’t have changed the statewide outcome, they could have cut into Romney’s margin. The same is true for Waterville, a city of about 17,000 people (10th largest in the state) in Kennebec County. There are other potential issues too. But so far, the state GOP is refusing to address the complaints or to alter its declaration of a 194-vote Romney victory.

But the questions may not go away. Washington County’s caucuses will be held this Saturday, and media outlets will surely be watching the results closely. It’s true that Paul fared poorly there in ’08, but he clearly has more support now; the question is whether he’s gained enough ground to beat Romney, and if he can do so by a margin big enough to cast new doubt on the statewide totals. The more Paul cuts into Romney’s lead on Saturday, the more pressure there will be for the state party to review the previous results.

The wild card in all of this is turnout on Saturday. Because it was so low statewide — just over 5,000 — a big spike in interest in Washington County could have a real impact. As Bill Nemitz of the Portland Press-Herald said on Rachel Maddow’s show last night, “the amount of attention focused on Washington County is unprecedented and their turnout on Saturday might eclipse the turnout from the rest of the state this past weekend.”

If Romney’s victory is ultimately overturned, timing will be key. Currently, the state GOP isn’t scheduled to meet until March, the Saturday after Super Tuesday. Depending on how the GOP race is progressing, having his Maine win tossed out then could be a serious blow to Romney — or it might not matter at all, if he’s coming off a series of big victories. But the timeline might also speed up. If (and it’s a very big if) Paul scores an emphatic victory in Washington County this weekend, it will be a lot tougher for the state Republican Party to run out the clock on this one.

This, of course, is the formula that Romney relied on to undermine Newt Gingrich when the former House speaker emerged as his chief rival in the run-up to last month’s Florida primary. In a way, Santorum is in basically the same position Gingrich was then, frantically playing financial and organizational catch-up after a breakthrough victory. So Gingrich’s Florida futility seems telling: Even with a major boost in fund-raising and a $5 million check from Sheldon Adelson, he was still outspent by Romney by an estimated $12 million on ads in Florida.

Now it’s Santorum’s turn to face this kind of disparity. Money has been flowing into his campaign like never before this past week and he’s found his own super PAC benefactor, but there’s just no way he and his allies will even come close to matching what the Romney forces will be able to spend in Michigan, Ohio and any other state they deem crucial to their strategy. What’s worse, the Wall Street Journal reported today that Adelson, who’s been sending signals behind the scenes that he wants to stay loyal to Gingrich but also wants to help Romney, may have found a way to reconcile his inner-conflict — funding ads that are ostensibly aimed at helping Gingrich but that actually do Romney a big favor by bashing Santorum.

If there’s a ray of hope for Santorum, it can be found in the content of Restore Our Future’s new attack ad, which blasts Santorum for votes as a senator to raise the debt ceiling and allow convicted felons to vote and for earmark requests. What’s striking is how little the Romney forces have to work with; after all, you can always find something to put in a 30-second attack ad, but the material being used here has an obscure/random feel to it. Santorum, with his generally consistent conservatism and lack of serious personal baggage, just doesn’t isn’t the same ripe target as Gingrich. When the Romney campaign needed to attack him, the ads literally wrote themselves:

So it’s fair to wonder how much punch the anti-Santorum ads will pack. Plus, Santorum — again, unlike Gingrich — is actually a generally competent candidate running a generally competent campaign. Which means his side wasted no time mounting a response to the Romney blitz:

Santorum doesn’t have the money to saturate the airwaves with ads like this. But his real aim may be to them to generate viral and free media attention and to convince influential conservatives around the country to rally to his defense and push the Mitt-as-bully narrative.