Two of democratic presidential candidate John Kerry’s stepsons are campaigning in Iowa today. Thirty-one-year-old Chris Heinz told a noontime crowd in Des Moines that he’d “like to see more humor and less anger” in the campaign debate. Heinz caught his step-father’s appearance last night on “The Daily Show” on the Comedy Central cable channel. Heinz says Kerry is “a very presidential person” but it was nice to see the more relaxed person Kerry is when he’s with his family. “John (Kerry) never laughs like that to my jokes,” Heinz said, laughing. “I guess Jon Stewart’s a professional comedian.” One of Stewart’s biggest jokes last night was about Heinz ketchup. Stewart asked Kerry if it was true that every time he used ketchup, Kerry’s wife gets a nickle. Teresa Heinz-Kerry’s first husband was an heir to the Heinz ketchup fortune, and her son tried to joke about Stewart’s joke today. Heinz joked that ketchup sales rose overnight after Kerry’s Comedy Central appearance. Heinz’ father died in a plane crash in 1991 and he says Kerry earned his respect, his friendship and then his love after Kerry married his mother. Chris Heinz campaigned in Ames this morning. Andre Heinz, his brother, will speak later this afternoon in Iowa City. President Bush’s twin daughters campaigned with him in Iowa on August 4th, but did not speak at the campaign rally in Davenport or speak with the media.