Hillary vs Obama: Round II?

Beinart pops a Republican pipe dream:

It's easy to see why conservatives would be salivating at the thoughtof a Hillary primary challenge. Presidents who face serious primarychallenges—Ford, Carter, Bush I—almost always lose. The last presidentwho lost reelection without a serious primary challenge, by contrast,was Herbert Hoover. But in truth, the chances that Obama will face aprimary challenge are vanishingly slim, and the chances that he willlose reelection only slightly higher. No wonder...