The FBI's former top lawyer defended the bureau's controversial surveillance warrant applications against a member of President Trump's 2016 campaign.

As general counsel, James Baker said he "wanted the burden on me to a significant degree" in preparing the paperwork to obtain Foreign Intelligence Surveillance Act warrants to wiretap one-time Trump campaign adviser Carter Page.

In front of a packed room at the Brookings Institution in Washington, D.C., Baker was prompted to discuss the Trump dossier compiled by ex-British spy Christopher Steele. The research was cited in the warrant applications, despite being largely unverified, and has become a flashpoint with GOP investigators who allege the FBI misled the U.S. Foreign Intelligence Surveillance Court.

At issue are the applications' lack of information about the Democrats who paid for the creation of the dossier and Steele's anti-Trump bias when the bureau applied to spy on Page, who was investigated by special counsel Roberat Mueller over his interactions with Russians but was never charged.

“You don’t want to put into a document like this gratuitous information about U.S. persons," Baker said moderator Benjamin Wittes. "You want to try to minimize it, to some extent. If it's important. If the assessment is that the identity is critically important and you need it to either follow the flow of the information ... then you might put the person's name in."

Baker noted that FBI lawyers are tasked with these kinds of questions and might find another reason to put identifying information in the applications.

The first warrant application was submitted in October 2016, after which there were three renewals at three-month intervals, including in January, April, and June 2017. The FBI's use of the dossier, contains claims about Trump's ties to Russia, has rankled Republican investigators on Capitol Hill, who are investigating possible bias in the upper echelons of the Justice Department and FBI.

A memo from the House Intelligence Committee in February 2018 alleged Steele was paid over $160,000 by the Democratic National Committee and Hillary Clinton's campaign through the Perkins Coie law firm and opposition research group Fusion GPS to "obtain derogatory information about on Donald Trump's ties to Russia." The memo also said the FBI never informed the Foreign Intelligence Surveillance Court of the dossier's Democratic benefactors or Steele's anti-Trump bias when it applied to spy on Page, who was investigated by special counsel Robert Mueller over his interactions with Russians but was never charged.

[Related: Trump dossier author Christoper Steele faced pre-2016 election deadline]

In a rebuttal to the House Intelligence Committee GOP memo, Democrats argued the Justice Department and FBI "met the rigor, transparency, and evidentiary basis needed to meet FISA's probable cause requirement."

But doubts about Steele's research and its use by federal agents remain. In public testimony after he was fired in May 2017, former FBI Director James Comey called at least some of the dossier's allegations "salacious and unverified." As recently as August 2018, the dossier continued to frustrate verification efforts. FBI official Jonathan Moffa told House investigators: "We, in an ongoing way, were looking at those facts, and doing that research and analytic work to try to verify, refute, or corroborate."

Baker, who is under criminal investigation for alleged unauthorized leaks to the media, has been subject to harsh criticism, including by President Trump. “Former FBI top lawyer James Baker just admitted involvement in FISA Warrant and further admitted there were IRREGULARITIES in the way the Russia probe was handled,” Trump tweeted in January. “They relied heavily on the unverified Trump ‘Dossier’ paid for by the DNC & Clinton Campaign, & funded through a big Crooked Hillary law firm, represented by her lawyer Michael Sussmann (do you believe this?) who worked Baker hard & gave him Oppo Research for ‘a Russia probe.’ This meeting, now exposed, is the subject of Senate inquiries and much more. An Unconstitutional Hoax.”

Baker was appointed FBI general counsel in January 2014 and reassigned by FBI Director Christopher Wray in December 2017. Last year, it was reported that Baker was resigning, and since has done writing for Lawfare and joined the R Street Institute.

During the event Friday, Baker stressed that he examined the FISA warrant applications on Page before they got signed and sent to the court. He said he was "comfortable" with their contents and was confident that the process remained "lawful." Regarding the FISA court, Baker said: “These are federal judges for goodness sake. They know how to evaluate wiretap applications. ... These are serious, serious judges."

Justice Department Inspector General Michael Horowitz is investigating possible FISA abuse, with a reported focus on Steele. Attorney General William Barr predicted that this probe could wrap up by the end of May or early June. Senate Judiciary Committee Chairman Lindsey Graham, R-S.C., said last week he will ask Supreme Court Chief Justice John Roberts to investigate possible abuse of the FISA court during the 2016 election.