Republican and Democratic leaders leveled their most forceful criticism yet against Donald Trump on Tuesday, widely denouncing the Republican presidential front-runner’s call to bar Muslims from entering the United States and signaling that Trump’s anti-immigrant and anti-Islamic rhetoric has agitated both parties more than ever.

At the White House, President Obama’s top spokesman said Trump’s proposal “disqualifies him” from the presidency, marking a rare administration foray into the 2016 race. On Capitol Hill, House Speaker Paul D. Ryan, R-Wisconsin, and Senate Majority Leader Mitch McConnell, R-Kentucky, said the idea was at odds with the values of their party and the United States as a whole.

In the space of a day, Trump’s role as a domestic political provocateur expanded to international agitator as he sent a first-of-its kind signal abroad: The leading presidential contender in the opposition party wants to keep Muslims out of the United States.

Leaders across the globe condemned Trump as officials at home worried about the long-term implications of his actions. Trump called Monday for a “total and complete” ban on Muslims entering the United States until we “figure out what is going on.” He reiterated his overall view on Tuesday.

It was far from clear whether the proposed ban on Muslims would have a negative effect on Trump’s popularity, which has only grown as he has escalated his rhetoric against illegal immigrants and a host of other groups. Some of his rivals treaded carefully around his remarks, and many of his most vocal critics stopped short of refusing to back him if he is the Republican nominee.

White House press secretary Josh Earnest said Trump’s proposal “disqualifies him from serving as president,” declaring that his rhetoric is “harmful to the country” and makes it harder to “work in partnership” with American Muslim leaders to identify potential threats.

REPUBLICAN CRITICISM

Ryan, who typically stays out of the Republican presidential contest, made a strongly worded exception.

“Freedom of religion is a fundamental constitutional principle. It’s a founding principle of this country,” Ryan told reporters. “This is not conservatism. What was proposed yesterday is not what this party stands for. And more importantly, it’s not what this country stands for.”

McConnell called proposals to bar visitors on the basis of their religion “completely inconsistent” with American values.

But neither Republican said he would reject Trump if he won the nomination, and Republican senators facing difficult reelections dodged questions about whether they would support the provocative businessman if he won the nomination. Almost all Republicans who were questioned tried to duck that possibility, saying only that they would support the eventual nominee.

Sen. Ted Cruz, R-Texas, wary of alienating Trump supporters as he tries to consolidate the conservative wing of the party, emphasized that he differed with that specific policy proposed by Trump.

“I disagree with that proposal. I like Donald Trump. A lot of our friends here have encouraged me to criticize and attack Donald Trump. I’m not interested in doing so,” Cruz told reporters.

Sen. Rand Paul, R-Kentucky, a long-shot near the bottom of the field, told a New Hampshire radio station that it is “a mistake to base immigration or moratoriums based on religion,” but added, “I’ve called for something similar.” Paul was referring to a measure that would suspend the issuance of visas to refugees from about 30 countries “that have large jihadist movements,” pending strict background checks.

TRUMP DEFENDS PLAN

After announcing his proposal– which he said was a response to recent terrorist attacks in Paris and California – he was greeted with adoration by his legion of fans on Twitter and at a raucous rally Monday night in South Carolina. On Tuesday, Trump conducted a contentious round of morning news-show interviews in which he defended the idea against critics who have deemed it unconstitutional, illegal, racist, dangerous and un-American.

Although Trump’s aides had initially said no one would be exempt from the “total” ban, the candidate began listing exceptions he would make. U.S. citizens who are Muslim and traveling abroad would be allowed to reenter, along with Muslim members of the U.S. military returning from tours overseas. Muslim leaders of foreign countries would also be allowed in, and exceptions would be made for athletes visiting the United States for competitions. In the interviews, Trump deflected questions and tried to talk over questions. During an interview on MSNBC’s “Morning Joe” that lasted more than 30 minutes, host Joe Scarborough told Trump to stop talking so that he could ask the candidate a question, then cut to a commercial.

Corey Saylor, a spokesman for the Council on American-Islamic Relations, predicted that Trump’s comments would make it easier for the Islamic State terrorist group to radicalize potential recruits.

“I think that Trump’s statement is a propaganda coup for ISIS,” he said. “No doubt in my mind about that.”

Some Democrats said Tuesday that the Republican Party is partly culpable in Trump’s rise.

“Republicans today are still saying they will support Trump if he is their nominee. Why? Because they are intimidated by his support and his supporters,” said Paul Begala, a strategist with the pro-Hillary Clinton super PAC Priorities USA Action. “Trump may be the monster, but the GOP establishment is the Dr. Frankenstein who created him.”

Many Republicans worry that Trump’s proposals will do lasting damage to a party desperately trying to cast itself as more tolerant and open than in previous presidential elections.

All of the Republican candidates have called for at least a pause in the acceptance of most Syrian refugees. Retired neurosurgeon Ben Carson has said that a Muslim should not be president and argued that accepting Syrian refugees into the United States is “a suspension of intellect.”

Sen. Marco Rubio, R-Florida, seen by many party leaders as the Republicans’ best hope for cross-party appeal, has equated Muslims with Nazis and dismissed complaints of anti-Muslim bias.

“Where is there widespread evidence that we have a problem in America with discrimination against Muslims?” Rubio said on Fox News Sunday night after Obama’s address to the nation urging tolerance.