RICHMOND, Va. -- Governor Tim Kaine said Madonna's allusion in a concert video to Republican John McCain alongside Adolf Hitler is "stupid."

But Kaine said Tuesday that Democrat Barack Obama has no duty to comment on what a pop star is saying about political figures in her new "Sticky and Sweet" concert tour.

In his monthly call-in show on Washington's WTOP radio, Kaine said he was unaware of the video montage. Played as part of the concert, the montage grouped McCain's picture alongside those of Hitler and Zimbabwe's dictator, Robert Mugabe.

When a caller to the show from Warrenton asked Kaine about it, he replied that if anyone is making that kind of characterization, "they're stupid and it's wrong."