President Donald Trump Donald John TrumpHR McMaster says president's policy to withdraw troops from Afghanistan is 'unwise' Cast of 'Parks and Rec' reunite for virtual town hall to address Wisconsin voters Biden says Trump should step down over coronavirus response MORE on Sunday raised questions about whether protesters who marched in Washington and around the nation a day earlier voted in the presidential election.

"Watched protests yesterday but was under the impression that we just had an election!" the president tweeted.

"Why didn't these people vote? Celebs hurt cause badly."

Watched protests yesterday but was under the impression that we just had an election! Why didn't these people vote? Celebs hurt cause badly. — Donald J. Trump (@realDonaldTrump) January 22, 2017

“Peaceful protests are a hallmark of our democracy,” he said in a later tweet. “Even if I don't always agree, I recognize the rights of people to express their views.”

Peaceful protests are a hallmark of our democracy. Even if I don't always agree, I recognize the rights of people to express their views. — Donald J. Trump (@realDonaldTrump) January 22, 2017

At least 3 million protesters on Saturday took to the streets of Washington, D.C. and cities across the world on the first full day of Trump's presidency, according to a review of official and unofficial estimates from the nation's largest cities.

ADVERTISEMENT

Large turnouts were reported in Boston, New York City, Chicago and Los Angeles as organizers for the main rally and march in Washington, D.C. grappled with a huge number of demonstrators.

Half a million people showed up at the National Mall and nearby streets for the Women's March on Washington.

At the event in Washington, D.C., a number of Democratic lawmakers and celebrities encouraged demonstrators to take action in the wake of a Trump presidency.

Feminist icon Gloria Steinem during the event called for Trump to unite the nation instead of divide it, saying that if the U.S. begins a registry of Muslims, then "we will all register as Muslims."

Sen. Bernie Sanders Bernie SandersMcConnell accuses Democrats of sowing division by 'downplaying progress' on election security The Hill's Campaign Report: Arizona shifts towards Biden | Biden prepares for drive-in town hall | New Biden ad targets Latino voters Why Democrats must confront extreme left wing incitement to violence MORE (I-Vt.) tweeted in support of the marchers. Former Democratic presidential nominee Hillary Clinton Hillary Diane Rodham ClintonHillicon Valley: FBI chief says Russia is trying to interfere in election to undermine Biden | Treasury Dept. sanctions Iranian government-backed hackers The Hill's Campaign Report: Arizona shifts towards Biden | Biden prepares for drive-in town hall | New Biden ad targets Latino voters FBI chief says Russia is trying to interfere in election to undermine Biden MORE also tweeted ahead of the march to thank the protesters.

--This report was updated at 9:38 a.m.