There is simply no comparison between Obama's connection to Farrakhan (none that I know of) and McCain's connection to Hagee (McCain has obsequiously courted Hagee's endorsement, and then held a joint rally with him). Despite his attenuated relationship, Obama "renounced and rejected" Farrakhan's endorsement because of his more repellent comments about Judaism, but McCain refuses to do anything of the sort with respect to Hagee. Josh Marshall has been all over this. And he makes exactly the right point in his commentary on Sen. Hutchinson's appearance on CNN today:

This morning on CNN's Late Edition, Wolf Blitzer asked McCain supporter Sen. Kay Bailey Hutchison (R-TX) about McCain's embrace of anti-Catholic and anti-Semitic Pastor John Hagee. There's a couple things to watch in this passage, first is how Blitzer completely misstates what actually happened. "Should John McCain repudiate and reject the comments, the support from John Hagee just as Barack Obama has done that with the Rev. Louis Farrakhan (sic)?"Let's be clear what happened here. John McCain solicited the support and endorsement of Hagee and then he held a joint appearance with Hagee in which he formally endorsed him. In these terms, Obama has no connection whatsoever to Farrakhan. He's just someone who said positive things about Obama. So the premise for even asking Obama is dubious in itself, whereas McCain has openly embraced Hagee.