A column in the New York Times, discussing the possibility of a primary challenge from the left against President Obama, observes, "it probably isn't coincidental that none of the last four American presidents to face primaries while seeking re-election — Johnson, Gerald R. Ford, Carter and George H. W. Bush — survived to serve another term."
The Times doesn't mention it, but there's a chance that a primary from the left might help President Obama by making him appear more centrist and less left-wing. For me, the presence of John Edwards and Dennis Kucinich and even on some issues (individual mandate for health insurance) Hillary Clinton in the Democratic debates and primaries in 2008 had that effect for Mr. Obama.
Winning the party's nomination and winning the general election that follows are two different things, and winning the general election requires not only winning over centrist independents but also mobilizing and energizing the party's base. But for all the press focus on the left-wing disappointment as a negative for Mr. Obama, I actually think there is some risk here for Republicans if the president tries to reinvent himself a la Bill Clinton after 1994 as a centrist tax-cutter.
It wouldn't be easy for Mr. Obama — there's still ObamaCare to worry about, though if Mr. Obama is running against Mitt "RomneyCare" Romney and a public-option leftist Democrat primary challenger that would tend to neutralize the health care issue. And there's still the issue of what happens to taxes in 2013.
My point is simply that for all the focus on the risk that a primary challenge would pose to Mr. Obama, it could also complicate things for the Republicans. On top of everything else I have mentioned, the drama of it could rob the Republicans of some of the airtime they would need to introduce themselves to the electorate.