Donald Trump’s latest campaign pledge, to ban Muslims from entering the United States, has caused widespread condemnation from those on both sides of the political aisle.

“Donald J. Trump is calling for a total and complete shutdown of Muslims entering the United States until our country’s representatives can figure out what is going on,” a press release from the campaign said on Tuesday.

A Trump spokesman later said this should apply to both immigrants and tourists.

The backlash was immediate.

This includes U.S. Senator Martin Heinrich, who took to Facebook on Wednesday morning to condemn Trump’s plan and compared it to the past and how his grandparents, immigrants from Germany, would have been treated during World War II under a similar proposal.

“Donald Trump’s latest comments are a rejection of American values and represent the worst ethnic and religious prejudices,” Heinrich said. “I am grateful that when my father and grandparents fled Germany in the years leading up to World War II, that our country chose to see them for what they were: enthusiastic American immigrants seeking to escape the dangerous politics gripping their former nation.

“Had this brand of twisted anti-immigrant logic been applied to them, I can only wonder how very different my life would be today.”

Speaker of the House Paul Ryan, R-Wisc., also criticized Trump’s plan, saying it “is not conservatism.” However, Ryan said he would support the Republican nominee, no matter who they are.

The White House Press Secretary took a different tact. Josh Earnest said the plan “disqualified him from serving as president.”

The plan is the latest in a long line of controversial plans by the real estate magnate who rocketed to the top of polls in the Republican presidential primary and has largely stayed there for months.

From the very beginning, Trump drew attention for his comments on Mexicans when announcing his candidacy.

But his proposal targeting Muslims seems could be another level of controversy. The proposal comes from a shoddy poll run by Frank Gaffney, a man labeled as an anti-Muslim extremist by the Southern Policy Law Center.

Republican presidential candidate Jeb Bush said that the United States should only accept Christian refugees from Syria. Another Republican candidate for president, Ben Carson, said that the United States should not elect a Muslim president and that the religion is inconsistent with the U.S. Constitution.