Ben Kreider, a student at Bowdoin College, said he was moved to protest by concerns over conscription.

“A lot of young people are afraid of the draft. It’s a real possibility,” he said.

For others, protesting was their only political outlet. “I think that one of the most important things is I am not 18,” said Molly Birnbaum, 17, a senior at the Packer School in Brooklyn Heights. “This is the only way I have my say. This is my vote.”

Several celebrities, including filmmaker Michael Moore, Rep. Charles Rangel, D-N.Y., and actor Danny Glover, also joined the protest. In a small rally before the march, they called for the return of American troops from Iraq.

“One day someone will ask: When our world went crazy and lives were lost, what were you doing?” Rangel said.

But not everyone in the crowds that lined Seventh Avenue opposed President Bush’s policies.

As the carnival-esque parade inched past Madison Square Garden, a gathering of pro-life and pro-Bush demonstrators held a small counter-demonstration across from Penn Plaza, engaging several protesters in charged shouting matches. Some labeled the demonstrators “baby-killers”; “Go home, fascists!” came the response.

One Bush supporter wore a t-shirt declaring “Islam supports Kerry.” Underneath was the slogan, “Intolerance is a beautiful thing.” Another carried a sign scrawled with the words, “Terrorists for Kerry.”

Robert Ashby, a College Republican at Western Kentucky University who was rallying the counter-protesters, dismissed the anti-Bush activists as “closed-minded.”

A police officer watching over the protest said that he would vote for the President. “I think he’s doing what’s best for the people. I think he has a good heart,” the officer said.

—Staff writers Michael M. Grynbaum, Jessica E. Schumer, and Joseph M. Tartakoff can be reached at grynbaum@fas.harvard.edu, schumer@fas.harvard.edu and tartakof@fas.harvard.edu.