Ed Kilgore at The New Republic has a look at this year's "Republican Civil War":
All across the country, Republicans are fantasizing about a gigantic electoral tide that will sweep out deeply entrenched Democratic incumbents this November. In their telling, this deep-red surge will be so forceful as to dislodge even legislators who don’t look vulnerable now, securing GOP control of both houses of Congress.
But could this scenario really come to pass? That will depend, in part, on
what type of Republican Party the Democrats are running against in the fall.
Hence the importance of this year's Republican civil war. In a string of GOP primary elections stretching from now until September, the future ideological composition of the elephant party hangs in the balance. Many of these primaries pit self-consciously hard-core conservatives, often aligned with the Tea Party movement, against “establishment” candidates—some who are incumbents, and some who are simply vulnerable to being labeled “RINOs” or “squishes” for expressing insufficiently ferocious conservative views.
Former congressman and talk show host J.D. Hayworth is threatening John McCain, a pariah to many conservatives for championing of immigration reform, among other sins dating back to 2000. (McCain recently gave Hayworth a gift by claiming he had been “misled” by Bush administration officials about the basic purpose of TARP funds in 2008. Not a terribly credible assertion, and it recalls George Romney’s famously self-destructive statement that he was “brainwashed” into supporting the Vietnam War.) McCain will probably survive, given his longstanding popularity in Arizona and help from Sarah Palin. But there's a wild card: If attorneys for the state Republican Party succeed in overturning Arizona’s open primary law, McCain could go down, providing a graphic illustration of the GOP’s rightward trend since 2008.