Trump’s insisting his campaign was spied on is 'part of the propaganda machine': Top Democrat “There is no evidence to support that spy theory,” said Rep. Adam Schiff.

A top Democrat on the House Intelligence Committee said the president’s repeated claims that the FBI spied on his presidential campaign are “a piece of propaganda the president wants to put out and repeat.”

California Rep. Adam Schiff told ABC News’ Chief Global Affairs correspondent and “This Week” Co-Anchor Martha Raddatz on Sunday that the president's assertions that the FBI infiltrated his campaign are an attempt to undermine special counsel Robert Mueller's investigation of Russia's interference in the 2016 election and possible ties to Trump associates.

"There's no evidence to support that spy theory," Schiff said.

"You have a president peddling these falsehoods and you have essentially people putting out propaganda" to promote that "fiction," the California Democrat said. "This is part of the propaganda machine. 'Let’s spread a completely fallacious story and then let’s say that it needs to be investigated and give it a life of its own.'"

"But it is resonating," Raddatz asked. "Just quickly, how do you counter that?"

Schiff responded, "There’s only one remedy for that, and that is you need to throw the bums out. As long as there’s a majority in Congress that is willing to do this president’s will and as long as we have a deeply unethical president, there’s only one remedy. And that is to change the Congress and to let the investigation go on."

The Democratic representative also commented on controversy surrounding the surprise appearance of two White House officials at a classified briefing on the Russia probe last week. The two officials, lawyer Emmet Flood and chief of staff John Kelly, left before classified material was discussed and the White House said they attended only to make brief remarks before the meeting.

But Schiff, who was at the briefing, said the officials' appearance at the congressional briefing was "improper."

He said it was “the Trump defense team’s effort to get information in an investigation implicating the president ... That is completely improper, it’s a violation of all the safeguards we’ve put in place after Watergate.”

Also on "This Week" Sunday, Senate Intelligence Committee member Marco Rubio, a Republican, said he hasn’t seen any evidence that the FBI was investigating the Trump campaign, but rather that it was looking at individuals who might have had ties to Russia.

“As far as what I have seen to date, it appears that there was an investigation not of the campaign but of certain individuals who have a history that we should be suspicious of that predate the presidential campaign of 2015, 2016,” the Florida senator said. “And when individuals like that are in the orbit of a major political campaign in America, the FBI, who is in charge of counterintelligence investigations, should look at people like that.”