It’s a conundrum for conservatives—Mitt Romney couldn’t get traction while he was playing to the base with his vice-presidential selection or his convention speech. But once he broke out the big Etch A Sketch in his first debate against President Obama, Mitt started soaring in the polls.

Of course, the reaction is not really a mystery—it’s a tried-and-true lesson of American politics: a more centrist candidate moves swing voters into his column, while a more extreme candidate alienates them. Mitt’s gains among moderates, the middle class, and women voters since the first debate are a direct result of this self-conscious re-centering of his presidential campaign.

The problem is that it goes against conservative chapter and verse, which says that a centrist Republican candidate all but guarantees a general election loss for the GOP.

This has always been a Catch-22 for Mitt Romney.

If he loses the general election, as he seemed likely to do before his first debate performance, conservatives will say that it was because he was a moderate from Massachusetts.

If he wins, they will say it was because he campaigned as a committed conservative who checked the box on every litmus test.

But President Romney would be seen as ideologically suspect by the far right from day one. The Tea Party caucus would announce their intention to hold his feet the fire and the first likely showdown would be on whether to raise the debt ceiling, pitting the businessman against the ideologues. The evidence suggests that Mitt would overcompensate to satisfy conservatives in Congress, but maybe the Oval Office would liberate him.

But away from the outside, the conservagencia—in other words, on Main Street, mainstream America—the question is more fundamental: who is the real Mitt Romney?

Is he the man who ran for Massachusetts governor as a proud progressive Republican, the son of a moderate Michigan governor in the mold of Ike and Rockefeller rather than Goldwater and Reagan?

Or he it the man who called himself a “severe conservative” at CPAC, the darling of right-wing talk radio in 2008, a consummate operator who obediently agreed to back every social-conservative plank from a constitutional ban on same-sex marriage to a constitutional ban on abortion?

This is not just a personal judgment call—it is a profound gamble with the presidency and therefore our nation’s future.

At the moment, Mitt Romney is a Rorschach test, with voters seeing what they want to see. That is the secret to his surge in the polls since the first presidential debate.

Conservatives have convinced themselves that Romney’s return to the center is a necessary election expedient, done with a wink and a nod. Swing voters who have swayed toward him believe that they have finally seen the real Mitt Romney and that he’s not the extreme candidate the negative ads (and the Republican primary process) led them to believe.

Look, I would be content if I thought that Mitt Romney’s election meant a revival of the centrist Republican tradition—deficit reduction driven by a sense of fiscal responsibility rather than a fealty to Grover Norquist that elevates anti-tax theology over balanced budgets and longterm economic stability. I’d like to see a cease-fire called on the culture wars, as Mitch Daniels once wisely suggested, and more consistent application of the principle of individual liberty. I’d like to see a problem-solving approach to the presidency that was open to the best ideas from both sides and realized that some degree of bipartisan cooperation was necessary to governing in the national interest. But as I write these words, I’m struck by how unconservative they sound in the current environment.

Mitt Romney will vaguely invoke all these ideas in the next debate, but they are in direct conflict with policy commitments made over the past five years of running for president.

Yes, maybe the salesman has just been doing what he needed to do to pull off the ultimate coup in a hyper-conservative party—nominate a Massachusetts moderate who once proudly claimed that he’d been a registered independent during the Reagan years. It could be just the kind of bold Hail Mary needed to re-center the Republican Party. Or maybe Romney doesn’t believe in any political idea bigger than his own ambition.

But the paradox of Moderate Mitt’s current success in the polls should provoke some soul searching inside the Republican Party. I don’t think many conservatives would seriously suggest that any of the alternative candidates this year—Gingrich, Santorum, Bachmann, or Cain among them—would be doing better against President Obama than Romney right now. (Christie or Jeb might have.) Mitt was the most plausible, responsible candidate out of that motley crew—and that was in large part because he was the most pragmatic and least hyper-partisan.

But after compelling Mitt to reverse his policy positions on almost every issue—abortion, guns, gays, the environment, and of course health care reform—from those he held when he was governor of Massachusetts, how will conservatives internalize his recent rise in the polls? Is it because he checked all the boxes and baptized himself a severe conservative? Or is it because he is convincingly returning to his centrist Republican roots? The most troubling answer would be that it doesn’t matter.