Organizers of the "World Can't Wait -- Drive Out the Bush Regime" event said 2,000 people turned out to demonstrate today. Chicago police estimated the crowd's size as about 1,500.

"World Can't Wait" earlier predicted 10,000 to 15,000 people would participate. At a similar rally held by the group in November, some 3,000 to 4,000 protesters marched.

As it was, today's march turned out to be much shorter than originally planned, after organizers were rebuffed in their efforts to extend their parade route throughout downtown Chicago.

A federal magistrate judge this morning denied the group's request for a temporary restraining order against the city, ruling their march would be restricted to a 3½-block route from the park to Federal Plaza in the Loop.

People started gathering shortly before noon in Grant Park at Jackson Boulevard and Columbus Drive. A podium was set up in the park, and speakers including actors, poets and political activists addressed the crowd on subjects ranging from torture of suspected terror suspects to the Bush administration's policies in Iraq.

Tribal drummers performed, participants carried protest signs reading "Out of Iraq" and "No War in Iran," and one man wore a mask of Bush and devil horns and a cape.

The event's emcee, a woman calling herself "Mars that revolutionary sister," told the crowd, "The future is counting on you today, this history-making day." She then read a poem critical of the Bush administration, touching on subjects ranging from poverty to Hurricane Katrina and the war in Iraq.

Rev. Bob Bossie, a member of Priests of the Sacred Heart who works at a social justice center in Chicago, said, "This is the culmination point of the last six years – of the immoral war, Abu Ghraib, Guantanamo and spying. It is the violation of everything I ever thought the United States meant."

As for exactly how the participants intended to "Drive Out the Bush Regime," Bossie and others each seemed to have a different idea.

Impeachment is too slow, he said, adding that the process needs to be something like what happened in Bolivia, "where people took to the street and forced the president to resign."

"Impeach them all and try them for war crimes," said Janet Melton of Chalmers, Ind., who wore a shirt stating, "I support Iraq veterans against the war" and held a sign saying, "No More Blood for Oil."

Referring to her 22-year-old daughter, who served in Iraq with the Army in 2004, Melton said, "When you find out she could have been killed on a pack of lies, it makes it so much worse."

Two weeks ago, Chicago members of "World Can't Wait" applied for a city permit to march 2 miles through downtown and up the northbound lanes of North Michigan Avenue. But the city agreed to let the protesters march only directly up Jackson Boulevard from the park to Federal Plaza.

U.S. Magistrate Judge Nan Nolan today did not reject or accept the claims of the group that the city dealt in bad faith in assigning it a shorter route.

But Nolan said the request for a restraining order came too late. It would be unfeasible at the 11th hour to reroute CTA buses and make alternate plans for emergency vehicles, she ruled.

The group agreed to schedule its march for 2 p.m. to allow time for vendors who work in Federal Plaza, located at Jackson Boulevard and Dearborn Street, to close their booths. The march took place uneventfully, with protesters parading between two rows of city police, Cook County Sheriff's police and Illinois State Police.

By 3 p.m., everyone was at Federal Plaza, and a round of speeches began again.

Police urged people who must travel downtown this afternoon to expect delays and to use public transportation if possible.

-- Tribune staff reporter Rudolph Bush contributed to this story.