CAMBRIDGE – Days after a controversial national emergency declaration from President Trump, hundreds of demonstrators weathered the snow and cold Monday afternoon in Harvard Square to protest policies of his administration.

US Representative Ayanna Pressley was among those to dismiss Trump’s recent declaration of a national emergency as “fake.” Pressley rattled off a series of problems she considered to be real emergencies: a dearth of affordable housing, soaring drug prices, gun violence, voter suppression, and climate change, among others. She called Trump’s declaration “constitutional vandalism” and an “abuse of power.”

“We will do everything to stop it,” the former Boston city councilor told the crowd gathered near Out of Town News, to cheers.

Pressley was not alone in those sentiments. Nancy Ryan, a 72-year-old retiree from Cambridge, was among the demonstrators outraged at Trump’s declaration of a national emergency. Ryan, sporting a bunch of pins that declared “Not my president,” was troubled by Trump’s border policy.

“I feel like it’s an imperial grab for power,” she said. “I worry about the courts at this point, whether they’re going to uphold the Constitution or let him get away with this stuff. It’s terrifying to me.”

The demonstration was one of many gatherings across the country to assail Trump’s declaration as undemocratic and anti-immigrant on Monday.

White House senior adviser Stephen Miller told ‘‘Fox News Sunday’’ that President Trump is prepared to issue the first veto of his term if Congress votes to disapprove his declaration of a national emergency along the US-Mexico border, according to The Associated Press.

On Friday, President Trump declared a national emergency along the southern border and predicted his administration would end up defending it all the way to the Supreme Court, reported the Associated Press.

The declaration gave Trump access to billions of dollars to build a border wall that Congress refused to give up, setting up a Capitol Hill clash over the separation of powers.

The move drew bipartisan criticism and multiple legal challenges. After lawmakers in both parties blocked his requests for billions of dollars to fulfill his signature campaign pledge, Trump’s declared national emergency shifts billions of federal dollars earmarked for military construction to the border.

Trump framed the declaration as a way to staunch a flow of drugs, criminals and illegal immigrants coming across the border, a problem that he considered to be a serious national security threat, according to The New York Times.

Democrats are planning to introduce a resolution disapproving of the declaration once Congress returns to session and it is likely to pass both chambers. Several Republican senators are already indicating they would vote against Trump — though there do not yet appear to be enough votes to override a veto by the president.

After addressing the crowd, Pressley said a real crisis the country is facing is the humanitarian one at the border. It’s unclear how many children are being separated from their families, she said. Illegal crossings are at an all-time low, she said, but people are being detained who are not criminals.

“They are being detained simply because they are immigrants,” she said.

She called for “compassion and comprehensive immigration reform.”

Cambridge Mayor Marc McGovern urged those who attended Monday’s rally to continue to resist Trump’s politics and rhetoric.

“We cannot stop when we have a person in the White House who is bent on hatred and racism and division,” he said.

On Presidents’ Day, some of the demonstrators held signs. One read: “We have nothing to fear but Trump himself.” Another: “No wall.” A third: “Power always corrupts.” Others held orange cartoon balloons of the president.

When the brass band honked out songs as snow fell, the tuba player’s instrument featured the message, “Your emergency is a lie!” Chants from the crowd included “Enough is enough!” A demonstrator wore a vest that said “Make Racists Afraid Again.”

Gail Epstein, a 66-year-old Cambridge resident who helped organize the demonstration, shared Ryan’s concerns. She called his declaration “a complete overreach” and said Trump’s values did not match those of the demonstrators.

“I don’t think that Trump deciding he wants to put a wall up is a national emergency,” she said.

Said Melrose resident Carol Sardo of Trump’s emergency declaration, “It seems to be bogus. That’s one of the reasons we’re out here.”

 

Material from the Associated Press and The New York Times was used in this report. Danny McDonald can be reached at daniel.mcdonald@globe.com. Follow him on Twitter @Danny__McDonald.