Democrats regularly insist the GOP has been captured by right wing extremists and only hard-line conservatives can prevail in the primary process.
How, then, do they explain the last two presidential nominees - Romney and McCain?
Both candidates vanquished more moderate, centrist rivals - Rudy Giuliani in 2008, John Huntsman in 2012 - as well as besting many competitors on their right. Republicans generally choose nominees from the broad mainstream at the center of the GOP, never selecting the most conservative or liberal alternatives. George W. Bush beat McCain to his left and Gary Bauer, Alan Keyes and others to his right; Bob Dole topped centrist Lamar Alexander and right-wingers Pat Buchanan and Phil Gramm.
The party last chose an anti-establishment, right wing firebrand fifty years ago - and Barry Goldwater's landslide defeat showed the dangers of that course.