3) Rush Limbaugh’s favorite slogan, “Conservatism wins every time,” is more a statement of wishful thinking than an accurate summary of electoral experience. It’s true that Ronald Reagan’s inspiring, comprehensive conservatism brought two sweeping victories (in 1980 and ’84). But the same supremely gifted candidate lost two prior runs for the presidency (in 1968 and 1976) to two charismatically challenged, moderate rivals, Richard Nixon and Gerald Ford.

Barry Goldwater electrified Republicans with his delineation of “The Conscience of a Conservative,” but he lost 44 states to the unspeakable Lyndon Johnson in 1964. More recently, tea party-affiliated candidates won several high-profile primary victories in 2010 and went on to ignominious defeats in easily winnable Senate races in Delaware, Nevada, Colorado and Alaska…

In short, the electoral experience of the last 50 years does nothing to undermine the common-sense notion that most political battles are won by seizing and holding the ideological center. In the last two presidential elections, more than 44% of voters described themselves as “moderate,” and no conservative candidate could possibly prevail without coming close to winning half of them (as George W. Bush did in his re-election).

The notion that ideologically pure conservative candidates can win by disregarding centrists and magically producing previously undiscovered legions of true-believer voters remains a fantasy. It is not a strategy. At the moment, it is easy to imagine Mitt Romney appealing to many citizens who would never consider Rick Perry or Herman Cain. It is much harder (if not impossible) to describe the sort of voter—Republican, Democrat or independent—who would refuse to support Mr. Romney (over Barack Obama!) but would somehow eagerly back Messrs. Perry, Cain or Gingrich, let alone Michele Bachmann, Rick Santorum or Ron Paul.