Progressive activists, Democratic leaders and ordinary voters gathered in crowds large and small around the country on Monday to protest the Trump administration and voice support for workers on the Labor Day holiday.

Hundreds of events were organized by labor groups, local activists and Democratic Party officials, adding to a drumbeat of demonstrations in recent months, including the “May Day” protests that took place on May 1, the widespread “No Kings” protests in June and those last month opposing President Trump’s push to redraw congressional lines.

Even if many of the events themselves have not always been very large, the regularly organized protests have signaled a desire among a broad swath of progressive groups and many left-wing voters to keep up the pressure on the Trump administration and provide a steady voice of opposition.

“We have to take a stand,” said Cathy McCook, 70, who waved a large American flag at a roadside protest with at least 200 people in a suburb of Orlando in Seminole County, Fla. The county’s voters backed Mr. Trump in 2024 after favoring Mr. Biden in 2020.

One of the biggest demonstrations was in Chicago, where Mr. Trump has discussed deploying National Guard troops to address street crime, which Democratic officials have vocally opposed. The threat of putting the military on patrol in Chicago, as Mr. Trump has already done on the streets of Washington, motivated many of those who turned out.

Speaking on a makeshift stage, the city’s mayor, Brandon Johnson, led a crowd of several hundred in a chant of “No troops in Chicago” and “Invest in Chicago.”