Sen. John McCain, R-Ariz., continued to try and use the Weather Underground to rain on Sen. Barack Obama, D-Ill., telling conservative bloggers in a conference call today that Obama needs to repudiate William Ayers, apologize to Sen. Tom Coburn, R-Okla., for comparing him to Ayers (as an example of a friend with whom Obama disagrees), and to apologize to the American people for his relationship with Ayers, "an unrepentant terrorist."The presumptive GOP frontrunner expresses surprise that the media is making more out of Obama's relationship with Rev. Wright than his relationship with Ayers.Town Hall, the American Spectator, Human Events, Commentary and others are up and running with the comments.McCain -- unlike the husband of Sen. Hillary Clinton, D-N.Y., who commuted the jail sentences of two members of the Weather Underground -- seems eager to bring this subject up, as he did on This Week with George Stephanopoulos on Sunday.- jptUPDATE: Obama spox Bill Burton writes to say, "We want to take Senator McCain at his word that he wants to run a respectful campaign, but that is becoming increasingly difficult when he continually tries to use the politics of association and makes claims he knows not to be true to advance his campaign. This type of politics of division and distraction, not only lead to a campaign not worthy of the American people, but also has failed to help our families for too long." McCain spox Brian Rogers responds: "Senator Obama was introduced to the local political scene at the home of an unrepentant terrorist, William Ayers, with whom he has had a friendship for many years. Mr. Ayers was a leader of the Weather Underground, a terrorist group responsible for countless bombings against targets including the U.S. Capitol, the Pentagon and numerous police stations, courthouses and banks. In recent years, Mr. Ayers has stated, 'I don't regret setting bombs . . . I feel we didn't do enough.' Then last week, Senator Obama went so far as to compare this unrepentant terrorist to Senator Tom Coburn, a physician who goes home to Oklahoma on the weekends and brings babies into life. Surely the American people agree that judgment matters in our next president. Senator Obama's long association with an unrepentant terrorist is an issue of judgment, and it will absolutely be an issue in this election."