Mitt Romney’s reputation as the shameless, uncontrollable flip-flopper of the 2012 race is now widely recognized and entirely locked in. It’s also well deserved — trying to find an issue on which Romney has been consistent is nearly impossible.

But as Paul Waldman explained yesterday, Newt Gingrich is nearly as bad, reversing course on all kinds of issues, including climate change, health care mandates, and U.S. policy in Libya.

So are the two leading Republican presidential candidates equally vulnerable on this? Not really. Waldman fleshes out the distinction between them:

[E]ven though they share some of the same flips, the way they happened illuminates something essential about who each man is and how they make decisions. Mitt Romney flip-flops carefully, after a period of calculation in which he determines the most appropriate strategic positioning required to achieve his short- and long-term goals. Newt Gingrich flip-flops impulsively, taking positions that sound good at a particular moment without any apparent regard for the past or the future. […]

Whenever Romney is asked to explain a flip-flop, he always has an answer, and it’s the same one he’ll give if he gets asked about it tomorrow or next month. It may not be entirely convincing, but you can tell he thought about it, worked through it with his advisors, and is offering the best explanation they could come up with. […]

Gingrich, on the other hand, has flip-flops that swing wildly from one extreme to another. His natural rhetorical style is one of extremity, in which good things are “profound,” “transformative,” and “fundamental,” while bad things are not just bad but horrific, the worst things that have ever happened. That means that when he embraces a position, it’s the greatest thing ever, and when he rejects a position, it’s the worst thing ever, even if what today is the worst thing ever was the greatest thing ever yesterday. Consequently, Newt finds himself saying things like, “Any ad which quotes what I said on Sunday is a falsehood.”

This is very persuasive. Romney, who has no core beliefs or principles, is constantly calculating, asking himself questions like “What do I have to say to advance my ambitions?” and “How will I explain this when I take the opposite position tomorrow?”

Gingrich is more of an erratic blowhard who sees such calculations as beneath him. He’s so impressed with the power of his intellect, Gingrich fully embraces every random thought that pops into his mind. When other thoughts occur to him, Gingrich can’t be bothered to consider or reconcile how they might contradict previous positions — he’s a visionary who has no time for such niceties.

As Jonathan Bernstein put it, “It’s not so much that Gingrich has taken the wrong position (from a conservative point of view) on various things; it’s the way he comes to it, which appears to be entirely personal and idiosyncratic…. [T]here’s no consistency or predictability at all.”

But there’s one other point I thought I’d add to the mix. If we were to list all of Romney’s and Gingrich’s flip-flops and compare theem, I suspect the totals would be fairly close. But I think Gingrich avoids the larger label because, while his positions have changed, his persona hasn’t. The disgraced former House Speaker may have inadvertently found himself on both sides of many policy disputes, but we can look back and see that Gingrich has always been, at his core, the same guy: a morally-bankrupt conservative Republican. The flip-flops are evidence of an impulsive mind and inflated ego, not cowardice.

Romney may flip-flop at least as often, but his personality and persona represent the polar opposite. Whereas Gingrich has always effectively been the same guy, Romney periodically enters cocoons and emerges as an entirely new person. Romney 1.0 was an independent who distanced himself from Reagan and H.W. Bush. Romney 2.0 was a moderate Republican, with liberal positions on social issues, who passed health care reform at the state level. Romney 3.0 was a social conservative who cared deeply about the culture war. Romney 4.0 was an experienced, above-the-fray voice for the GOP establishment who had no use or time for the party’s Tea Party wing. Romney 5.0 loves Tea Partiers, signs right-wing pledges, and hates “career politicians.”

They’ve both taken flip-flopping to impressive heights, but they’re not the same kind of flip-floppers.

Steve Benen

Follow Steve on Twitter @stevebenen. Steve Benen is a producer at MSNBC's The Rachel Maddow Show. He was the principal contributor to the Washington Monthly's Political Animal blog from August 2008 until January 2012.