He walked down a side street, eyes darting here and there, wondering how it would unfold.

"What kind of fences will the police have? Will they bring dogs?" Hatem Abudayyeh asked. He stopped in the shadow of the United Center, home of the NBA's Bulls and the NHL's Blackhawks and a draw for tens of thousands of pro-Palestinian demonstrators who are expected to protest against U.S. support for Israel at the Democratic National Convention this month. "I hope they don't militarize it," he said. "The first statement the police made was about mass arrests. They've backed off a little. But they're trying to intimidate us."

The son of Palestinian immigrants, Abudayyeh is one of the march's organizers and has long been at the center of civil rights protests. He was investigated by the FBI more than a decade ago — no charges were brought —and in 2017 he helped block traffic at Chicago O'Hare International Airport over then-President Trump's Muslim travel ban. The demonstration he is preparing comes as this onetime city of stockyards and slaughterhouses hopes it can avoid the chaos and police brutality that marked the antiwar protests that engulfed the Democrats' convention here in 1968.