He was in Philadelphia on Monday for a “debate” with former Senator Max Cleland, the Georgia Democrat who lost an arm and two legs in Vietnam. Mr. Cleland lost his 2002 re-election bid after his Republican opponent, Saxby Chambliss, questioned his commitment to domestic security, running an advertisement featuring likenesses of Osama bin Laden and Saddam Hussein. Many Democrats remain bitter over that defeat, for which Mr. Cleland still largely blames Mr. Rove.

“It’s a source of income for me,” Mr. Cleland said of the Monday joint appearance, sponsored by an insurance trade group, for which he said he was paid $15,000. (Mr. Rove’s speeches reportedly bring $40,000.)

Going up against Mr. Rove, Mr. Cleland said, “is like going up against the devil himself.”

It can pay to be the devil himself, or at least thought of that way. “There is an incredible amount of interest in what Karl Rove has to say,” said Howard Wolfson, an adviser to Senator Hillary Rodham Clinton’s presidential campaign, who appears with Mr. Rove on Fox News.

Mr. Wolfson said he was amazed by how often Democrats asked him what Mr. Rove was like off the air. “When I say he’s nice, people look at me like I’m nuts,” he said.

Mr. Rove declined an interview for this article, but engaged somewhat by e-mail. He said little on the record, ignored some questions and was dismissive of others. “Look,” he wrote, “I don’t mean to be rude but I have so much on my plate that my brain explodes when you ask questions like how much of my time I spend on each of my activities or how did I apply skills to my new chapter, et cetera. I can answer simple questions of fact but I am stretched through the election.”

But it clearly delights him, for instance, that Senator John Kerry of Massachusetts went on about “the smears of Karl Rove” during his speech at the Democratic National Convention in August. Mr. Rove helpfully pasted a passage from Mr. Kerry’s speech on Rove.com, under the headline “The Losers Have Spoken.”