The Intercept asked prominent Republican lawmakers on Capitol Hill on Tuesday if they reject Donald Trump’s conspiracy theory that American Muslims are shielding terrorists.

Trump said in a speech Monday that Muslims “have to work with us. They know what’s going on. They know that [the Orlando shooter] was bad. They knew the people in San Bernardino were bad. But you know what? They didn’t turn them in.”

Despite the fact that Trump’s speech was covered by CNN, NBC, MSNBC, Fox News, the New York Times, the Washington Post, and elsewhere, many lawmakers pled ignorance about his remarks.

“Honestly, I do not know what Mr. Trump said because I’ve been working on the defense bill,” Sen. John McCain, R-Ariz., told us. “But are American Muslims cooperating with law enforcement authorities?” we followed up. “You can say whatever you like, sir, but I have not seen any of it,” he said, and ducked into an elevator.

McCain has condemned anti-Muslim conspiracy theories in the past, even among his supporters. During the 2008 presidential election, McCain was praised for telling a crowd of supporters that then-Sen. Obama was “not an Arab” and “a decent family man and citizen.” McCain was booed by his supporters.

Sen. Mark Kirk, R.-Ill., also refused to comment. “I didn’t see Donald Trump’s speech,” he told us. We asked him if he thinks Muslims are cooperating with law enforcement. He repeated himself and then entered an elevator, leaving us behind.

Kirk is in a tight Senate race against Rep. Tammy Duckworth, D.-Ill., who criticized him for his previous support of Trump. Last week Kirk rescinded his endorsement of Trump over comments Trump made about U.S. District Judge Gonzalo Curiel. But Kirk previously came under fire in 2005 for saying that he is “OK with discrimination against young Arab males from terrorist-producing states.”

Sen. Bob Corker, R.-Tenn., refused to say anything about Trump’s remarks other than that he was “somewhat discouraged by the direction things are going, in the campaign itself.”

“I don’t feel like I have to respond to everything that’s being said out there,” Corker said.

You would think this would be an easy conspiracy theory for Republican lawmakers to reject: the bigoted accusation that 3.3 million American Muslims are identifying and shielding terrorists in their midst. But you’d be wrong.

Some lawmakers expressed uncertainty.

Rep. Peter King, R.-N.Y., the powerful former chairman of the House Homeland Security Committee called it a “difficult question,” and said “we’ll talk some other time.” In 2011, King received backlash from the Muslim community for saying that “80 percent of Mosques in this country are controlled by radical imams.”

“I have to make that assumption, I don’t know,” Rep. Rob Bishop, R-Utah, said, when asked whether American Muslims were cooperating with law enforcement. “You’re asking me for a definitive answer. I have no basis to make that answer. I don’t know.”

When confronted with Trump’s words, Rep. Frank Guinta, R-N.H., repeatedly stated that he didn’t see the speech so he didn’t want to comment. After being asked whether Muslims in particular are cooperating with law enforcement, he offered the nonanswer: “All law-abiding Americans are cooperating with law enforcement.”

Some Republicans cautiously stood by Trump’s remarks.

“I’m certain not everyone is cooperating. I do agree not everyone is cooperating,” Rep. Blake Farenthold, R-Texas, said. We followed up by asking if it’s true that Muslims are systematically teaming up to withhold information from law enforcement. “I don’t have any facts to judge the truth of that statement. I don’t have enough facts to judge whether that’s true or not,” he concluded.

“I haven’t heard what he said, or any details about it,” said Rep. Barry Loudermilk, R-Ga., Asked whether he thought American Muslims were cooperating, Loudermilk said “I think that it’s segmented. Some are. Some aren’t.”

Only one lawmaker interviewed by The Intercept was willing to plainly reject Trump’s remarks. Sen. Jeff Flake, R.-Ariz., who has called on members of his party to withhold endorsements from Trump. When asked whether American Muslims are withholding information about terror plots, Flake said “I see no evidence of that.” He went on to denounce an immigration ban on Muslims entering the United States.

“That’s why I’ve always said that a ban on Muslims, a religious test, it’s wrong. It’s constitutionally inconsistent,” Flake said. “More than that, it’s the opposite strategy we should employ if we want to win the war on terrorism, and identify the .001 percent of those who want to do us harm. The last thing we want to do is go out and offend the 99.99 percent of those Muslims that feel the same way that everybody else does.”

The idea that American Muslims are systematically shielding terrorists is unfounded. The community has actually been active in preventing terrorism. In the 12 years that followed the September 11 attacks, almost two out of every five al Qaeda plots in the United States were prevented thanks to tips generated from American Muslims, according to a database compiled by the Muslim Public Affairs Council.