In which a man possessed of legendary flip-flop kung fu, whom some in the green lobby are backing precisely because they don’t believe a word he says about skepticism towards man-made climate change, beats up on an opponent for not being true to his word. Stuart Rothenberg wrote a column just yesterday arguing that Mitt’s vacillations are actually one of his great strengths in the primary because, no matter how far right his rhetoric may stray, centrists discount it on the surefire assumption that he’s lying for electoral advantage. It’s the Republican version of liberals shrugging at Obama’s ultra-cynical, decades-long “evolution” on gay marriage. And yet, here’s Mitt’s take today on The One: “He doesn’t want to share his real plans before the election.” Er, yeah. Don’t you hate candidates like that?

All right, deep breath. I had to get that off my chest before we shift to blind circle-the-wagons mode for the new nominee. In fact, as Guy Benson argues, Romney’s attack on O today was pretty sharp. And while he didn’t use the words “Etch-a-Sketch,” there may be a method to the madness of trying to paint Obama as the flip-flopper in the race. It’s not Romney being oblivious to his own record, it’s simple strategy:

Mitt Romney has decided the best defense is a good offense. Derided as a “flip-flopper” by President Obama? Throw the charge back in the president’s face. Attacked for his plan to revamp Medicare? Fire back that Obama has already crippled the popular entitlement program.

That was the central theme of the all-but-inevitable Republican presidential nominee’s speech Wednesday to the Newspaper Association of America: Try to take evident vulnerabilities of his own candidacy and turn them against the current White House occupant. As Romney pivots toward the general election – and after Tuesday’s victories, this week seems to mark a line of demarcation between the primary and general elections – it hints at a major part of his strategy to unseat Obama.

Romney has been knocked repeatedly – by Republican and Democratic critics alike – for changing position on issues like abortion-rights and gay marriage. But during his speech, he listed a series of Obama’s own flip-flops he deemed “election-year conversions.” The list included corporate tax rates, regulation, and energy policy.

That’s an interesting twist on the Rovean game plan of reframing your opponent’s greatest strength as a weakness, but maybe Mitt had no choice. What’s Obama’s “great strength” at this point? His landmark domestic “achievement” is on life support at the Supreme Court and the long-hoped-for economic recovery hasn’t yet picked up serious momentum. He’s the rare president who’s going to try to win a second term by making the election a referendum on his challenger, so here’s Romney trying to head him off at the pass by neutralizing one of the Democrats’ strongest attack lines.

And of course he’s right in what he says about Obama’s habit of torching Republican straw men. O might have gotten a standing ovation from the reporters in the room after yesterday’s speech (whereas Romney did not after today’s), but that didn’t stop the AP from dropping this fact check on him for treating opposition to the mandate and cap and trade, among other things, as uniquely GOP phenomena. Take two minutes to read, especially if you’ve forgotten which Democratic presidential candidate was pro-mandate in 2008 and which was anti.