Ever since Mitt Romney began tarring Obama as a job destroyer based on a bogus metric — the “net” jobs lost on his watch — a few of us (see Steve Benen) have been trying to document every twist and turn in Romney’s dissembling. Much of Romney’s argument is based on the idea that Obama should be held responsible for the hundreds and hundreds of thousands of jobs lost in the months just after he took office, when the economy was in free fall — before his policies took effect.

As I noted last week, the Romney campaign is betting that he can lull the American people into forgetting just how severe a crisis Obama inherited upon taking office. The “net” job loss metric is central to this effort to inflict mass amnesia on the public.

Yet despite the fact that this argument is absolutely central to Romney’s case against Obama, it has drawn very little media scrutiny.

So it’s good to see that Paul Krugman has devoted an entire column to it today, labeling Romney the “amnesia candidate”:

Mr. Romney constantly talks about job losses under Mr. Obama. Yet all of the net job loss took place in the first few months of 2009, that is, before any of the new administration’s policies had time to take effect. So the Ohio speech was a perfect illustration of the way the Romney campaign is banking on amnesia, on the hope that voters don’t remember that Mr. Obama inherited an economy that was already in free fall.

How does the campaign deal with people who point out the awkward reality that all of the “Obama” job losses took place before any Obama policies had taken effect? The fallback argument — which was rolled out when reporters asked about the factory closure — is that even though Mr. Obama inherited a deeply troubled economy, he should have fixed it by now. That factory is still closed, said a Romney adviser, because of the failure of Obama policies “to really get this economy going again.”

...he’s basically attacking Mr. Obama for not acting as if George Bush had been given a third term. Are the American people — and perhaps more to the point, the news media — forgetful enough for that attack to work? I guess we’ll find out.

The degree to which Romney has been able to skate by with this argument is truly remarkable. It’s the basis of Romney’s entire rationale for running for president. He has repeated it in every conceivable forum for months on end. Yet it has gone almost entirely unexamined by the news media. One hopes Krugman’s column today will begin to change that.

* No end to Romney’s dissembling: Relatedly, Post fact checker Glenn Kessler knocks down another one: That Obama is to blame for business start-ups declining by 100,000 per year on Obama’s watch. This, too, is rooted in the free-falling economy Obama inherited — something the Romney campaign wants you to forget.

* Arizona immigration law front and center: The Supreme Court will hear the challenge to the Arizona immigration law this week, which will intensify attention to immigration at exactly the moment when Romney, who has suggested he sees Arizona’s approach as a “model,” is beginning to pivot towards the general election in order to make inroads among Latinos.

Today Romney is set to campaign with Marco Rubio, which may again draw attention to the fact that Romney’s immigration adviser Kris Kobach has said he views any GOP DREAM Act that doesn’t require self-deportation as unacceptable.

* Obama fails leadership test on non-discrimination executive order: Jonathan Capehart unloads on the President for punting on the executive order banning federal contractors from discriminating based on sexual orientation. As Capehart notes, this is a clear-cut case where Obama has failed to show the sort of leadership on gay rights we’ve become accustomed to from this administration.

Also: The White House’s claim that it is pushing for a broader legislative solution instead just doesn’t hold up. No such solution is going to pass Congress.

* Romney’s contempt for public disclosure: A nice piece by Jae C. Hong tying together Romney’s refusal to release tax returns and his unwillingness to divluge his major campaign bundlers: “Mitt Romney’s contemptuous attitude towards the importance of public disclosure is increasingly troubling.”

* Fun fact of the day: Taegan Goddard ferrets out a good one from a USA Today piece on the massive amount of dark money flooding the campaigns:

“More than $8 out of every $10 collected during the first three months of this year by two conservative groups associated with Republican strategist Karl Rove, for instance, went to a non-profit branch that does not have to reveal its donors.”

* More (gulp!) good news about economy? Also from USA Today, a survey of economists finds they think the economy will grow faster than expected this year, and if this comes to pass, public perceptions of the direction of the economy could prove decisive for Obama this fall.

* Obama to ratchet up use of executive power: Charlie Savage, on the administration’s increasing reliance on the use of executive orders to circumvent Congress:

Aides say many more such moves are coming. Not just a short-term shift in governing style and a re-election strategy, Mr. Obama’s increasingly assertive use of executive action could foreshadow pitched battles over the separation of powers in his second term, should he win and Republicans consolidate their power in Congress.

Note Savage’s reporting about how the strategy is rooted in the White House’s epiphany about the inability to secure any bipartisan cooperation on anything.

* It’s all about Elizabeth Warren’s likeability: Glen Johnson on a hidden dynamic in the Massachusetts Senate race: Scott Brown’s likeability is already a given, meaning the race will likely turn on whether Warren can successfully resist the GOP effort to drive up her negatives.

This is why Republicans keep hitting Warren as a hypocrite (for some reason it’s hypocritical to want to raise taxes on your own class, yourself included) and an elitist professor (for some reason Republicans think Massachusetts voters will see her intellectual credentials as a bad thing).

* And the conservative media fabrication of the day: It appears Fox News has quietly added a few words to Obama’s silver-spoon remark, quoting him this way:

Unlike some people, I wasn’t born with a silver spoon in my mouth.”

Emphasis mine. What else?