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Rosenstein acknowledges problems with FBI's Russia probe but defends Mueller's appointment

(CNN) Former Deputy Attorney General Rod Rosenstein said Wednesday he would not have signed off on a foreign surveillance warrant used in the FBI's Russia investigation, but he defended his appointment of former special counsel Robert Mueller to investigate Russian election interference and President Donald Trump's associates.

Rosenstein testified Wednesday before the Senate Judiciary Committee in Senate Republicans' first hearing taking aim at the origins of the FBI's Russia investigation. Senate Judiciary Chairman Lindsey Graham, a South Carolina Republican and close Trump ally, pressed Rosenstein on whether Mueller should have been appointed at all, given that no conspiracy was ultimately found between Trump's team and Russia.

"The whole concept that the campaign was colluding with the Russians, there was no there there in August 2017. Do you agree with that general statement?" Graham asked

"I agree with that general statement," Rosenstein responded.

But the former No. 2 at the Justice Department, who supervised the Mueller investigation, said there was "reasonable suspicion" to investigate and the probe was properly opened, even if no conspiracy was ultimately found. Appointing Mueller was the correct call, Rosenstein said.

"I believe at the time, senator, and I still believe it was the right decision under the circumstances," Rosenstein said. "I think it's important to establish that an independent investigation found that the Russians sought to interfere in the election and that no Americans conspired with them."

Rosenstein's testimony is the first in a series of hearings that Graham is planning as part of a probe challenging the origins of the FBI's investigation into Trump's team and Russia, known as Crossfire Hurricane, and the Mueller probe, which followed it. Ordinarily, the testimony of the former deputy attorney general who supervised a special counsel investigating the sitting president would be a significant news story, but it was overshadowed Wednesday by the Covid-19 pandemic and the nationwide protests in response to the death of George Floyd .

"We have looked at Russia's role in the election. Now we're going to look at the Mueller investigation. And we're going to look hard," Graham said. "We're going to be looking at the Mueller appointment in May of 2017, to see if there was a crime worthy of being investigated. ... We're going to be talking about how it got off the rails, who's responsible for it getting off the rails."

Graham and Senate Homeland Security and Governmental Affairs Chairman Ron Johnson, a Wisconsin Republican who has launched his own committee probe into the FBI's investigation into Trump's team, are holding separate votes Thursday that would give them wide-ranging subpoena power for documents and testimony of top Obama administration officials.

Republicans are seeking to unravel the FBI's Russia investigation on the heels of Attorney General William Barr's move to dismiss the charges against Trump's first national security adviser, Michael Flynn, whose guilty plea was secured by Mueller's team. The charges against Flynn are the latest source of controversy over the FBI probe, as former acting Director of National Intelligence Richard Grenell declassified documents that Trump and other Republicans have claimed show the Obama administration was targeting Flynn.

In his testimony Wednesday, Rosenstein walked a fine line between praising Mueller's integrity, agreeing the investigation was not a "hoax," and saying he could not "vouch" for the allegations being investigated.

"We investigate people who are not necessarily guilty," Rosenstein said. "I didn't have any presumption that these folks were guilty of anything."

Rosenstein acknowledged the problems with the Foreign Intelligence Surveillance Act warrants obtained on former Trump adviser Carter Page that were documented by the Justice Department inspector general. Asked if he would have signed the warrant renewal in 2017 again had he known what's been disclosed since, Rosenstein said, "No, I would not."

Rosenstein says Mueller probe wasn't influenced by political bias

Still, Rosenstein defended Mueller and his investigation, saying that it was not influenced by political bias and was not targeting Trump. "Based upon my conversations with him, I'm fairly confident political bias did not enter into that investigation," Rosenstein said.

Rosenstein disputed several Republican accusations lobbed at the Russia investigation and the prosecution of Flynn, which is currently being litigated after DOJ moved to drop the charges. He disagreed with Sen. John Kennedy, a Louisiana Republican, that Flynn hadn't lied.

"I certainly was not under the impression that he hadn't lied. As I think I made quite clear, I was under the impression that Gen. Flynn had willfully lied to the FBI and the vice president," Rosenstein said.

Rosenstein also disputed allegations from Tennessee GOP Sen. Marsha Blackburn that Flynn "was a target because he supported Donald Trump."

"It's important for you to know, I read the pleading that was filed, and I know people have jumped to the conclusion there may have been wrongdoing by the prosecution. I haven't seen that allegation raised by the attorney general," Rosenstein said.

But Rosenstein said he understood the frustrations Trump expressed over the probe. Trump repeatedly called the investigation a "witch hunt" and a "hoax," and many of his attacks were directed at Rosenstein.

"I do not consider the investigation to be corrupt, senator, but I certainly understand the President's frustration, given the outcome, which was in fact that there was no evidence of conspiracy between Trump campaign advisers and Russians," Rosenstein said.

Democrats have dismissed the Republican investigations as an election-year effort to boost Trump's reelection bid and rewrite the history of the Mueller investigation. Senate Democrats charged Wednesday that the Judiciary Committee should be focused on addressing more important issues, like the Covid-19 pandemic and the nationwide protests over policing, rather than relitigating the Russia probe.

"Those who tuned in might have expected we had a hearing concerning the public health crisis facing America, the pandemic we're fighting every day," said Sen. Dick Durbin, an Illinois Democrat.

Democrats pushed back on Republican allegations surrounding the investigation, arguing that the problems with the Page FISA warrant did not affect Mueller's investigation and that the opposition research dossier cited in the FISA warrant was not part of Mueller's final report.

"Contrary to the President's claims, IG Horowitz found no evidence of political or anti-Trump bias in the Crossfire Hurricane investigation," said Sen. Dianne Feinstein of California, the top Democrat on the Senate Judiciary Committee. "IG Horowitz confirmed that none of the FISA errors his investigation uncovered call into question 'any part of the special counsel's report.'"

Rosenstein signed off on FISA renewal

Rosenstein, who testified voluntarily, was not present for the start of the Russia probe in July 2016, but he signed off on the third renewal of a FISA court warrant approved for Page -- warrants that the inspector general concluded were undermined by significant problems.

The inspector general report outlined 17 "significant inaccuracies and omissions" in the four applications for the Page warrants in 2016 and 2017, including the use of an opposition research dossier on Trump and Russia. But Horowitz also found the FBI investigation had been properly started, with enough predication to probe suspicious ties between people associated with the Trump campaign and suspected Russian agents.

Republicans pressed Rosenstein to explain why he didn't ask more questions to uncover the problems with the warrant and verify the information. Rosenstein said it wasn't his role to verify but argued he properly reviewed the application.

"I don't believe I was rubber-stamping, senator," he said in during a contentious exchange with Sen. Ted Cruz of Texas.

Rosenstein suggested that then-acting FBI Director Andrew McCabe could have been more forthcoming to him about what was happening at the FBI in surrounding the investigation in May 2017, following the firing of FBI Director James Comey. The comments prompted McCabe to issue a statement disputing Rosenstein's characterization.

Many of the major events of the Mueller investigation happened on Rosenstein's watch.

Rosenstein oversaw the Mueller investigation for almost two years, from his May 2017 appointment of the special counsel -- following then-Attorney General Jeff Sessions' recusal from the investigation -- until Barr took office in February 2019, the last full month for Mueller's work.

Rosenstein was the top Justice Department official overseeing the indictments of Russians for election interference and the major obstruction and conspiracy prosecutions of Trump advisers, including former campaign chair Paul Manafort and his deputy Rick Gates, the President's personal attorney Michael Cohen, longtime friend Roger Stone and Flynn.

It was Rosenstein's directive in Mueller's initial months, too, that outlined how the special counsel should investigate whether Page, Manafort and foreign-policy campaign adviser George Papadopoulos colluded with Russian government officials. Mueller's team did not find evidence of any conspiracy between Trump's associates and Russia, but he did conclude that those inside and associated with the Trump campaign had welcomed and encouraged Russian activity they thought could help Trump win.

Rosenstein has maintained even since his departure that Russians interfered in the 2016 election and will likely continue to in 2020.

Rosenstein also became a major witness to the other half of the Mueller investigation: documenting the President's attempts to obstruct the probe. Trump was not charged with obstruction after Barr and Rosenstein reviewed the Mueller report, Barr told Congress after he received Mueller's findings.

This story has been updated with additional developments Wednesday.

CNN's Evan Perez contributed to this report.