On Thursday, at a campaign event in Stockton, Calif., McCain even poked fun at Obama's relative youth. Obama is 46.
"I admire and respect Sen. Obama," McCain said in a tone that some took to be sarcastic. "For a young man with very little experience, he's done very well."
Late Friday afternoon, the McCain campaign unexpectedly released the 2006 tax returns of his wife, Cindy. They showed that she earned more than $6 million, more than $4.5 million of which was listed as coming from "rental real estate [and] royalties." Mrs. McCain, who files her taxes separately from her husband, paid $1.7 million in taxes. She had previously refused to release her personal income tax returns.