The person or persons who "committed the felony" of releasing classified information to the media concerning former national security director Michael Flynn alerted Russia to how their communications are being tracked, and that could prove a "detriment to our national security," Sen. Chuck Grassley said Tuesday.
"They can take action so that we lose that source of information on the Russians in the future," The Iowa Republican told Fox News' "America's Newsroom" anchor Bill Hemmer.
"One of our tools is less valuable than it previously was."
On Monday, Grassley, chairman of the Senate Judiciary Committee, asked both former deputy Attorney General Sally Yates and ex-Director of National Intelligence James Clapper, during their testimony before his subcommittee, if either had served as anonymous sources for press reports about President Donald Trump or his sources, or if they had asked other people to act as those sources.
Both Yates and Clapper said that they had not.
Clapper's questions came after Trump attacked Yates through his Twitter account, tweeting that he thought the subcommittee should ask her about leaks from the White House.
"When it comes to the unmasking, we can find out who allowed the unmasking," Grassley said, referring to the decision to reveal names of people who had been involved in intercepted communications with Russians. "That may lead to people who committed the felony of releasing it to the press."
Meanwhile, Clapper reiterated that there was no direct evidence of collusion with Russia and Trump, leading Trump to claim in a tweetstorm that Yates had made the "fake media" unhappy because she did nothing but repeat "old news."
Grassley said did not like to respond "to what is called fake news," as it was "news, and it's analysis that's accurate, because Clapper made that very clear in public." Grassley said he had heard the same thing in a classified briefing.
The senator, though, did not agree with Trump's assessment that Clapper's statements were "old news," as he was "step-by-step going through the four or five times he had conversations with people at the White House. As far as I'm concerned that is new news...those details are new but it might not be anything new in the outcome."
Grassley also said he does not know yet if there has been a violation of the law forbidding revealing the names of Americans, but that will be something he will examine further with Sen. Lindsey Graham, R-S.C.. He said he also assumes Sen. Sheldon Whitehouse, D-R.I., the ranking Democrat on the subcommittee, will want to pursue the matter.
"When those things happen, we need to know if there was a violation of law, and we want to make sure that Americans are protected with their constitutional right of privacy, and we want to make sure that when there is an unmasking, that it's for a legitimate purpose," said Grassley.
More importantly, it is important to determine of the names were unmasked for political purposes, said Grassley.
President Barack Obama's national security adviser Susan Rice admitted in April that she was the one who asked that the names of American citizens be unmasked, but insisted she did not leak any of the names to the media.
"Susan Rice may be the answer to this if she appears before our committee, the purpose of the unmasking and what she knew about it," Grassley said Tuesday. "If it was used for political purposes, that's absolutely wrong."
Grassley said he is not sure Graham has formally asked Rice to testify, but if he has and she refuses to appear, there could be an inference made that she's hiding from the committee.
There is a limited number of people who could have leaked names to The Washington Post and other media outlets, said Grassley, agreeing with statements Graham made to Graham on monday.
"I have no basis for saying if it's 10 or 50," said Grassley. "It is a limited number high up in an organization. We ought to be able to isolate it. When you isolate it you ought to be able to find out who released it.