Despite Arianna's claim, that's what he tells Bill O'Reilly. Transcript comes via a PR firm I assume is promoting her new book: 

O'REILLY: OK. Arianna Huffington says you didn't vote for Bush in 2000. She's one of these people who is going to come after you.
O'REILLY: On her website yesterday, somebody blogged that you collaborated with the North Vietnamese, and they didn't torture you. This is Arianna Huffington. Now Arianna Huffington flat out said you did not vote for President Bush in 2000.
MCCAIN: What can you say?
O'REILLY: Did you vote for President bush?
MCCAIN: Of course not. I campaigned all over this country for him.
O'REILLY: So you voted for President Bush.
MCCAIN: Of course. I mean, that's a ridiculous question.
O'REILLY: So she lied?
MCCAIN: Well, I don't -- frankly, I do not read Huffington Post. I spare myself from having that experience.
O'REILLY: You voted for Bush in 2000?
MCCAIN: I voted for Bush in 2000 and 2004.
MCCAIN: And not only that, far more important than a vote, I campaigned everywhere in America for him.
MCCAIN: I enjoyed it. I campaigned with him. I did everything I could to get him elected and reelected president.

Is it possible McCain was talking to Arianna about the Arizona primary? That's the one scenario in which neither one is lying....

--Michael Crowley