* Romney claims about Bain and jobs collapsing under scrutiny: As I’ve been saying, the battle over the meaning and true nature of Mitt Romney’s tenure at Bain will be central to the general election campaign, and today the war is set to escalate in a big way.

There are now signs that the national press is getting serious about getting to the bottom of what really happened during this central and defining episode of Romney’s life and career. The Associated Press has weighed in with a bracing fact check of Romney’s frequent claim that he created 100,000 jobs at the company:

Romney has never substantiated his frequent claim that he was a creator of more than 100,000 jobs while leading the Bain Capital private equity company. His campaign merely cites success stories without laying out the other side of the ledger — jobs lost at Bain-acquired or Bain-supported firms that closed, trimmed their workforce or shifted employment overseas. Moreover, his campaign bases its claims on recent employment figures at three companies — Staples, Domino’s and Sports Authority — even though Romney’s involvement with them ceased years ago.

By that sort of charitable math, President Barack Obama could be credited with creating over 1 million jobs even though employment overall is down about 2 million since he came to office. But Romney accuses Obama of destroying jobs while using a different standard to judge his own performance — cherry-picked examples that leave everything else out.

That’s what I’ve been saying! Another way to put this: The core claims that form the whole foundation of Romney’s case that he’d be better on jobs than the president have been unmasked as entirely bogus.

As we’ve seen previously, the Romney campaign regularly continues telling its preferred falsehoods even after getting called out on them. The question is whether the particularly ludicrous nature of this one will make telling it so much of a liability that the Romney camp will drop it for political reasons, which I suppose would be better than nothing.

* Special bonus Romney dissembling: As Steve Benen notes, Romney is now claiming he did factor in layoffs under Bain into his calculations, even though his campaign previously said only job gains were being counted.

* More light shed on Bain years: Relatedly, the Wall Street Journal has taken the most comprehensive look yet at Bain’s record on Romney’s watch. After analyzing 77 businesses Bain invested in under Romney, the Journal concludes that Bain raked in huge profits even as the companies it aquired didn’t fare too well:

22% either filed for bankruptcy reorganization or closed their doors by the end of the eighth year after Bain first invested, sometimes with substantial job losses. An additional 8% ran into so much trouble that all of the money Bain invested was lost.

While the story does say some of the findings could burnish Romney’s overall claims, it also concludes that the high rate of difficulties suffered by firms invested in by Bain “could undermine a central thrust of Mr. Romney’s campaign message: that his private-sector experience building companies makes him the best candidate to turn around the ailing U.S. economy.”

* Dems turn up heat on Romney’s Bain tenure: Relatedly, the DNC is ratcheting up the attacks on Romney’s Bain years, releasing a new Web video that takes direct aim at the math Romney is using to calculate the 100,000 jobs supposedly created on his Bain watch. The video features commentators pointing out that he isn’t counting the jobs lost.

Separately Dems are going to push the Bain issue hard today, with DNC chair Debbie Wasserman Schultz targeting it in interviews and a press conference today, according to a Dem official. This, again, is another sign that Dems know how dangerous it could be if Romney succeeds defining Romney’s Bain years on his own terms.

* Gingrich Super PAC targeting Bain years, too: It’s not just Dems and MoveOn: A pro-Gingrich Super PAC is set to go up on the air in South Carolina with ads featuring Bain layoff victims giving emotional interviews about what Bain did to their lives and communities. A GOP strategist says Republicans need to understand how vulnerable Romney will be on this score in a general election:

“David Axelrod is going to have a heyday with this, and Republicans need to know this story before we nominate this guy.”

Imagine this sort of footage airing in ads blanketing struggling Rust Belt communities, and you get the idea.

* Could Gingrich’s new attack damage Romney? Steve Kornacki on why it’s not out of the realm of possibility that the Bain years could become a liability, even in a GOP primary.

* Gingrich calls Romney’s Bain years “plundering”: It’s a risk for Gingrich to attack Romney in a GOP primary this way, but Gingrich tells Byron York he’s standing by it:

“I don’t think a Milton Friedman or a Hayek would say to you, rich guys have to go and rip off companies and leave a wreckage behind,” Gingrich said in an interview after a town hall appearance here Sunday night. “I think that’s plundering. I don’t think that’s capitalism.”

That, coming from a fellow Republican, might make it into Dem ads, too.

* How Obama’s advisers view Romney: Dan Balz boils it down:

Obama’s advisers view Romney through two prisms. Through one they see a formidable opponent who can make the economic argument against the president more effectively than any of the other Republicans running and who has been disciplined in the way he has carried himself so far. Through the other, they see someone whose career in the private sector has left him vulnerable to questions about whether he can truly connect with the independent, middle-class voters who will decide the November election.

Romney’s advisers see it differently. They do not believe this election is about empathy but about effective leadership and results.

* Should Obama replace Biden with Hillary? Bill Keller makes the case, arguing it’s the single best way to guarantee an Obama second term.

* Another payroll tax cut fight looms: Roll Call on the trepidation Republicans are feeling about having this fight again after the Dems’ “serious messaging win” at the end of last year.

* And the Republican non-response to inequality: Mitt Romney and others like to dismiss the Dem case about inequality by arguing that they believe in equality of “opportunity,” but as Paul Krugman notes, there’s no evidence that they are actually willing to do anything to increase social mobility in the real world.

What else is happening?