romney sits atop what may be the most radical major political party in American history. If he wins

The longer he campaigns, and shifts shapes, the less we can be sure about what he actually believes. We tend, however, to put too much stock in what our elected leaders believe - and not nearly enough in the dominant ideology of their party and political base.

George W. Bush, for instance, wanted to reform our immigration policies, but he couldn't persuade his fellow Republicans in Congress to support a path to legalization for undocumented immigrants. Today's Republicans, radicalized by a virulently anti-immigrant tea party, would be even less receptive to such policies. To win their support, Romney was the most anti-immigrant candidate in the GOP primary field; today, he's strategically quiet on immigration matters. Even if Romney has moderated his views - a big if - there's little basis for believing he can persuade his party to follow suit. So it goes with his policies on Obamacare (a few popular aspects of which he now says he would keep), his shift on the availability of employer-provided contraceptives and more.

While Romney has become a general-election tabula rasa, he sits atop what may be the most radical major political party in American history.

Regardless of Milquetoast Mitt's positions, a government with a Republican president and Republicans in control of the House and Senate would use its budget-reconciliation powers (which enables a Senate majority to sidestep the 60-vote requirement so frequently used to stymie legislation) to defund or repeal not only the health-care guarantees and financial regulations that Obama signed into law but also much of the education funding and regulatory safeguards on which Americans have depended for decades.

The radicals who dominate the Republican Party have entertained Romney's turn to the center as a necessary electoral expedient. The day after a Romney victory, their blitzkrieg will begin - leaving the moderate Mitt of the general election to historians specializing in short-lived phenomena.