The FBI Director told the Senate Homeland Security and Government Affairs Committee on Thursday that it would be difficult for a foreign government to change the outcome of a national election through mail-in ballot fraud.
"Now we have not seen, historically, any kind of coordinated national voter fraud effort in a major election, whether it's by mail or otherwise we have seen voter fraud," said FBI Director Christopher Wray, appearing before the committee to discuss threats the homeland faces. "Certainly to change a federal election outcome, by mounting that kind of fraud at scale would be a major challenge for an adversary, but people should make no mistake, we're vigilant," he said.
His comments came as President Donald Trump has repeatedly warned of widespread fraud as the result of expanded mail-in voting.
When asked about ways to combat malign foreign influence, Wray encouraged voters to be "critical thinkers" and to get their news from a variety of sources.
Director of the National Counterterrorism Center Christopher Miller and DHS Senior Official Performing the Duties of the Deputy Secretary Ken Cuccinelli also appeared before the committee Thursday. A similar hearing occured in the House last week.
Last week, Wray echoed the intelligence community's assessment that Russia is actively continuing to try to influence the U.S. election.
"The intelligence community's consensus is that Russia continues to try to influence our elections, primarily through what we would call malign foreign influence, as opposed to what we saw in 2016, where there was also an effort to target election infrastructure, cyber targeting," he said.
The Trump administration, and the president in particular, has repeatedly claimed that China is a bigger threat to election security than Russia.
"But Chris, you don't see any activity from China, even though it is a FAR greater threat than Russia, Russia, Russia. They will both, plus others, be able to interfere in our 2020 Election with our totally vulnerable Unsolicited (Counterfeit?) Ballot Scam. Check it out!" the President tweeted shortly after Wray's testimony last week.
In an early August statement, the office of the Director of National Intelligence singled out Russia, China and Iran as potential disruptor countries during the 2020 election.
On Thursday, Wray said he can't rank the those three countries in terms of which is the biggest threat to the 2020 presidential election and that each country is focused on a different issue.
"I don't think I could really rank them, I mean all three are ones that we're very concerned about in different ways. So it's not really an apple to apple comparison," he explained.
He also sidestepped the question on Chinese election interference.
"As I mentioned before, in many ways, [China is] our greatest counterintelligence threat to this country and their malign foreign influence efforts are different. As Mr. Cuccinelli said, different from the Russians but much broader and wider, in terms of their reach to not just federal officials but state local officials, and they use economic leavers very heavily."
Wray also tackled the issue of protests around the country. The FBI director reiterated a point he made last week in front of the House that the FBI does not investigate the ideology of demonstrators.
"Now let me be clear, we do not investigate groups or individuals based on ideology or on the exercise of First Amendment protected activity alone but when the ideology leads someone to commit criminal acts and pursue violence, the FBI will not hesitate to take appropriate action," he said.
Wray testified that that his agency is working with state and local law enforcement officials to see if federal charges can be brought against some of those protesters who have been arrested.
Cuccinelli was put on the spot when asked about two whistleblower complaints DHS is facing.
Former DHS Intelligence and Analysis director Brian Murphy claims he "was instructed by Mr. Wolf and/or Mr. Cuccinelli to modify intelligence assessments to ensure they matched up with the public comments by President Trump on the subject of ANTIFA and 'anarchist' groups."
"Oh absolutely that did not happen," Cuccinelli said, adding that the language in a DHS upcoming threats report on white supremacists was not toned down, as was alleged.
Democrats on the House Homeland Security committee also announced last week the start of a new investigation into allegations from a detention facility nurse, including reports that ICE detainees in the Irwin County Detention Center were subjected to hysterectomy operations without their full understanding or consent.
ABC News has not confirmed this reporting.
Cuccinelli said that the allegations were "shocking" and that he immediately dispatched a team outside of ICE, including a Coast Guard attorney and an Army nurse, to review records at the Georgia facility.
"I'm happy to report that, at this stage the inspector general is still doing a more in depth review, but at this stage the documentation indicates that there were, over the course of four years, two hysterectomies were performed on two women and that is confirmed by the nearby medical facility where those procedures took place. They came to the same numerical conclusion that that we did but, as I said, the inspector general is continuing to investigate that."
National election fraud would be 'a major challenge for an adversary': FBI director