Senate Minority Leader Chuck Schumer's three planned book tour events scheduled for this week were abruptly postponed Monday morning because of "security concerns."

Schumer, promoting his new book "Antisemitism in America: A Warning," faced backlash over voting for the House-approved government funding bill that averted a shutdown on Friday. With Democrats' help, the Senate passed the stopgap bill hours before funding was set to lapse.

Many Democrats, including progressives, had wanted him to vote against the bill and to more strongly protest against President Donald Trump's and congressional Republicans' agendas.

Schumer had events planned in Baltimore, New York City and Washington, D.C., this week. Protests were planned outside of all three events.

A spokesperson for Schumer's book tour told ABC News that "due to security concerns, Senator Schumer's book events are being rescheduled."

Some of the hosts of Schumer's events, including D.C. bookstore Politics and Prose and Baltimore's Enoch Pratt Free Library, also individually cited security concerns for the cancellation.

Schumer has been facing steep criticism from his own party for voting for the funding bill.

After announcing that he would be a no vote on the proposed spending plan -- a decision that could have led to a government shutdown -- Schumer later said from the floor he would vote yes.

The switch-up earned him the praise of Trump, but the ire of prominent Democrats, and comes as the party struggles to mount a cohesive response to actions by the Trump administration that are reshaping the federal government, immigration policy and other key issues.

Schumer, defending his decision to vote for the funding bill, said in a speech on the Senate floor on Thursday that while he did not approve of what was included in a funding bill, a government shutdown would be worse.

The Senate Minority Leader said that a shutdown would give Trump and Elon Musk, who has overseen major cuts to the federal government, more power to make decisions about what to cut, and that the shutdown would cause pain to American families.

"For Donald Trump, a shutdown would be a gift. It would be the best distraction he could ask for from his awful agenda," Schumer said.

In a CNN appearance on Friday, Schumer framed the decision as a way to protect the Democratic Party, while downplaying intraparty disagreement over the path he took.

"My job as leader is to lead the party," Schumer said. "And if there's going to be danger in the near future, to protect the party. And I'm proud I did it. I knew I did the right thing, and I knew there would be some disagreements. That's how it always is."

Schumer also denied any insinuation he didn't have the "overwhelming support" of his caucus, suggesting members had thanked him for his position.

Schumer is set to appear on ABC's "The View" on Tuesday, March 18.

Among the groups that had been organizing protests of Schumer's book tour events was the Progressive Change Campaign Committee PAC (PCCC), which wrote in an email on Sunday, "We need to make an example of Schumer and send a message to all Democratic officials that we want BACKBONE."

"Now is the time to channel public anger, not hide from it," PCCC co-founder Adam Green told ABC News on Monday after the events were postponed. "People are serious about Democrats not having a plan to fight Trump."

Another major Democratic-aligned group, the Indivisible Project, called on Schumer to step aside as leader of the Senate Democrats in a statement on Saturday. Indivisible had also been planning on protesting outside of the Baltimore event.

Schumer "led the charge to wave the white flag of surrender," Indivisible co-executive director Ezra Levin wrote in the statement.

Levin praised Schumer for his work in the Senate, but said that his actions had failed both the United States and the Democratic Party.

"Senator Schumer has contributed to and led many important accomplishments that Indivisible is grateful for. But with our democracy on the line, he let us, the country, and the Democratic Party down… Senator Schumer should step aside as leader. Every Democrat in the Senate should call for him to do so, and begin making plans for new leadership immediately," Levin wrote.

The controversy also comes as recent polling shows Americans feeling disillusioned toward the Democratic Party. An NBC News poll published on Sunday (but taken before the government funding vote) found that only 27% of registered voters feel favorable about the party.

ABC News' Averi Harper, Isabella Murray and Karen Travers contributed to this report.