Crowds gather to listen to Sen. Bernie Sanders, I-Vt., during a No Kings protest on Saturday in Washington. (AP Photo/Allison Robbert)

WASHINGTON (AP) — Large crowds of protesters marched and rallied in cities across the U.S. Saturday for ” No Kings ” demonstrations decrying what participants see as the government’s swift drift into authoritarianism under President Donald Trump.

People carrying signs with slogans such as “Nothing is more patriotic than protesting” or “Resist Fascism” packed into New York City’s Times Square and rallied by the thousands in parks in Boston, Atlanta and Chicago. Demonstrators marched through Washington and downtown Los Angeles and picketed outside capitols in several Republican-led states, a courthouse in Billings, Montana, and at hundreds of smaller public spaces.

Trump’s Republican Party disparaged the demonstrations as “Hate America” rallies, but in many places the events looked more like a street party. There were marching bands, huge banners with the U.S. Constitution’s “We The People” preamble that people could sign, and demonstrators wearing inflatable costumes, particularly frogs, which have emerged as a sign of resistance in Portland, Oregon.

It was the third mass mobilization since Trump’s return to the White House and came against the backdrop of a government shutdown that not only has closed federal programs and services but is testing the core balance of power, as an aggressive executive confronts Congress and the courts in ways that protest organizers warn are a slide toward authoritarianism.

In Washington, Iraq War Marine veteran Shawn Howard said he had never participated in a protest before but was motivated to show up because of what he sees as the Trump administration’s “disregard for the law.” He said immigration detentions without due process and deployments of troops in U.S. cities are “un-American” and alarming signs of eroding democracy.

“I fought for freedom and against this kind of extremism abroad,” said Howard, who added that he also worked at the CIA for 20 years on counter-extremism operations. “And now I see a moment in America where we have extremists everywhere who are, in my opinion, pushing us to some kind of civil conflict.”

Trump, meanwhile, spent the weekend at his Mar-a-Lago home in Florida.

“They say they’re referring to me as a king. I’m not a king,” the president said in a Fox News interview that aired early Friday, before he departed for a $1 million-per-plate MAGA Inc. fundraiser at his club.

A Trump campaign social media account mocked the protests by posting a computer-generated video of the president clothed like a monarch, wearing a crown and waving from a balcony.