United States Sen. Chuck Schumer has postponed his book tour following intense criticism of his vote for a Republican-backed spending bill, the New York Times reports.

Schumer’s new book, Antisemitism in America: A Warning, co-written with Josh Molofsky, was published Tuesday by Grand Central. A critic for Kirkus called the book “an urgent warning about resurgent prejudice against Jewish people.”

Schumer, a New York Democrat and the Senate minority leader, had been scheduled to embark on a nationwide tour to promote the book in cities including New York and Washington, D.C.

But last week, Schumer shocked some members of his party by voting for a Republican stopgap bill that prevented the federal government from shutting down, joining eight other Democratic senators. The bill passed and was signed by President Donald Trump.

Schumer’s decision sparked outrage among many Democrats, with one liberal group, Indivisible, demanding that Schumer step down from his leadership post. Activists online indicated that they planned to protest Schumer at his book tour appearances.

USA Today quoted Risa Heller, a spokesperson for the book tour, as saying, “Due to security concerns, Senator Schumer’s book events are being rescheduled.” There is no word on when the book tour might take place.

Michael Schaub is a contributing writer.