That's whyand joked that under President Bush's tax plan, Vice President Dick Cheney can claim the president as a dependent.
Kerry also joked that he wanted running mate John Edwards to stand in the vice presidential debate, but Cheney wanted to sit. "We compromised and now George Bush is going to sit on Dick Cheney's lap," he said.
Craig Crawford looks at - and sometimes laughs at - politics for Congressional Quarterly.
"I think a lot of politicians and consultants have figured out that humor is a real bridge to people. It's a way for politicians to be human," says Crawford.
"And that's something that a lot of politicians unfortunately, need to stress: that they are actually human."
Kerry and President Bush are carrying on in the comic tradition observed by candidates and presidents through the ages.
In the '90s, Clinton showed off his showmanship on Arsenio Hall's show.
In the '60s, Richard Nixon cracked people up with four famous words on the show "Rowan & Martin's Laugh-In": "Sock it to me."
Even Herbert Hoover, whose term was depressing in so many ways, tried to get a laugh by suggesting the symbol of the Democratic Party should be a rabbit. "I recommend the magician's animal as the symbol of the New Deal party. It travels in uncertain directions at very high speeds and it multiplies rapidly," he joked.
It is a centuries-old practice.
Mark Katz, a speechwriter who refers to himself as "the guy who made Mike Dukakis so funny," says the funniest joke from a U.S. president came from Abraham Lincoln.
"Someone's accused him of being two-faced," says Katz. "And he said, 'If I had two faces, do you think this is the one I'd be wearing?' It's a good joke."
Katz is also one of many who made Al Gore so funny, and Bill Clinton. He writes joke-filled speeches for Democrats.
"At the end of the day, you want people saying, 'I like that guy.'"
His counterpart on the Republican side, Landon Parvin, has written for the Reagans, President Bush and his father.
"The purpose is for him to be better liked when he sits down than when he first stood up. That is what humor can do," says Parvin.
Katz and Parvin write for opposite sides following the same rule: Political humor works best when turned inward. So President Bush makes fun of his elocution: ""I'm working on my electrocution."
"I arrived at my three rules of political humor. Be self-deprecating. Repeat as necessary - rule number two. And once you've been sufficiently self-deprecating, you've acquired the right to be self-deprecating on behalf of others," says Katz.
When there was no shortage of other people deprecating him, President Clinton took the offensive with a masterpiece of self-deprecation.
Katz helped write a mini movie for a Washington gathering near the end of Clinton's second term. It was Bill Clinton: "Home Alone."
"At the time, there's a lot of talk about him being left alone in the White House. You know, the first lady was running for senator. The vice president was running for president. And there was this idea of him left alone - you know, unattended. You know, no one caring who was president, and he was still in office"
Of course, at the time there was a lot in Clinton's life that he might not have considered funny - but he still had to laugh at.
Katz recalls, "First of all, there was a lot of legal stuff going on. I mean, there were things that he could not say because his lawyers would not allow him to say - in fact, one of the speeches he gave at the Gridiron Club in 1998, the premise of which was, 'Here's the speech my lawyers wrote for me. Written 'Knock knock. Don't answer that.'"
In 1982, Nancy Reagan was facing her own kind of crisis. She was being lambasted for her opulence. She turned to Landon Parvin for help. He wrote a song to the tune of 'Second Hand Rose.'
"Second hand clothes. I'm wearing second hand clothes. They're quite the thing in spring fashion shows. Even my new trench coat with fur collar, Ronnie bought for ten cents on the dollar."
Nancy sang it much better than that, got great reviews, and kinder coverage in the news media.
But Katz and Parvin both know humor can backfire. Especially this year, when the country is not in a very funny mood.
Parvin learned that the hard way when he wrote a now infamous bit about the Iraq war for President Bush.
"The joke got a good laugh that night, and then it was turned into political fodder by the other party," says Parvin.
Parvin thinks Washington isn't as funny as it used to be.
"There is a lot of bitterness, and humor should be able to help that bitterness to help heal it. But, it's not being allowed to," he says.
But Parvin and Katz are still in business - wary of the line between good humor and bad taste - and looking for the next great line.