UPDATE 2-Protesters across U.S. denounce Trump's emergency declaration

Activists gathered in cities across the United States on Monday to support immigrants and denounce President Donald Trump's declaration of a national emergency to build a U.S.-Mexico border wall. More than 1,000 marched in New York's Union Square, while several hundred turned out in Washington and Chicago and others converged in dozens of cities on the Presidents Day holiday, calling Trump's declaration an abuse of power, a usurpation of Congress and a manufactured crisis.

Organizers from the advocacy group MoveOn.org said 250 events were planned nationwide. Trump has built his base of support in the Republican Party on taking a hard line against illegal immigration, calling the wall necessary to stop crime and illicit drugs.

He invoked the emergency powers on Friday after Congress declined to fulfill his request for $5.7 billion to help build the wall that was his signature 2016 campaign promise. His move aims to let him spend money appropriated by Congress for other purposes. The move is likely to face a legal challenge.

In New York's Union Square, critics hoisted signs with messages such as "Impeach" and "Emergency? Call 1-800-STABLE-GENIUS," mocking Trump's description of himself. "It sets a terrible precedent, and the idea that we would waste this kind of money on something like this when we have so many more pressing problems is horrendous," said Sandy Radoff of the anti-Trump advocacy group Rise and Resist.

Melissa Levy had planned to go to the dentist but instead took her two daughters, ages 11 and 15, to the protest. Levy identified herself as the daughter of a Holocaust survivor and said the father of her children was an immigrant, calling immigrants "the heart and soul of this country." "I'm outraged and disgusted. The idea that the president would have the audacity to undermine all the checks and balances that our Constitution put in place is very disturbing to me," Levy said.

About 10 counter-protesters in New York waved a Trump 2020 flag and chanted: "Build the Wall!" Police separated them from the main protest. Protesters in Chicago's Federal Plaza carried signs that read "Dump Trump" and "Fake Emergency," and chanted: "No wall, no fear, immigrants are welcome here."

Cheryl Krugel-Lee, a 32-year-old student, said she brought her 4-year-old daughter to the protest in freezing weather to set an example. "This was a power grab by the Trump administration, and it's immoral and illegal," Krugel-Lee said. (Reporting by Gabriella Borter in New York and Robert Chiartio in Chicago; Additional reporting by Barbara Goldberg in New York; Writing by Colleen Jenkins and Daniel Trotta; Editing by Dan Grebler and Peter Cooney)