Atrios reminds us that there's something of a backstory to the Rush-McCain relationship that could help explain the harshness of McCain's denunciation of Rush today: Back in 2000 when insurgent McCain was threatening Bush's casual stroll to the GOP nomination, Rush attacked him relentlessly for weeks and weeks on end.

Of course, McCain has happily patched things up this year with plenty of other folks on the right who he didn't get along with in 2000. So in the unlikely event that McCain gets the nomination, all will be forgiven and he'll be a happy guest in Rush's studio. But the backstory is interesting.