Let the evolution begin.

As presidential candidates jockey for recognition with 21 months to go until Election Day, the editorial cartoonists are poking around for caricatures that fit each contender—or deciding whether some of them are even worth learning to draw.

Any editorial cartoonist will tell you that a caricature is never that much about what the person looks like; while an artist might capitalize on some telling imperfection, in the end it’s about how he or she perceives the person.

Eventually cartoonists reach a consensus on how a public figure is drawn. Take the President: Over six years, caricatures of George W. Bush have undergone a regression, from man to ape to a stunted sort of prosimian with large ears and beady eyes, at a rate about equal to his decline in popularity.

“There is an evolutionary process,” says Matt Davies, the Pulitzer Prize–winning editorial cartoonist for the Journal News in New York state. “It really parallels the basic knowledge of the character of these people.”

Davies describes the consensus as giving Bush a small, “arrow-shaped” nose and a big upper lip, neither of which matches Bush’s actual physique.

“It’s not a physical thing for me at all,” says Clay Bennett of the Christian Science Monitor, another Pulitzer winner. “The easiest to caricature would be the candidate with whom I agree the least. Cartooning is a reactionary form of journalism, based on negatives more than positives.”

Looking ahead to 2008, it’s John Edwards who gives Davies nightmares—and not for political reasons.

“He looks like a Ken doll,” Davies says. “We thrive on the grotesque. We root for the ugly guy. I think cartoonists would be mortified if John Edwards becomes president.”

Cartoonists have had more practice with the bigger names—Hillary Rodham Clinton and John McCain—but even in those cases most say they are withholding judgment on how the caricatures will evolve.

“Sometimes it takes you a little while to capture a person,” Bennett says.

When Davies first tries to get a feel for a person on the sketch pad, he says he sometimes lands on an image of someone or something else that reminds him of his subject’s essence.

“Al Gore was a person who was difficult to draw. There’s no consensus, in the way there is for Clinton or Bush.” Then for Gore he found his muse: Sam the Eagle from the Muppets.

“I thought, that’s who Al Gore is,” he says. “I drew him with that in mind.”