Deputy Attorney General Rod Rosenstein, the second-in-command at Main Justice, faced mounting pressure Friday to recuse himself from overseeing the investigation of Russia's alleged meddling in the 2016 presidential election.

Enter Rachel Brand, the first woman to ever serve in the No. 3 role of associate attorney general, who now finds herself next in line to oversee that investigation. But only if Rosenstein steps aside.

President Donald Trump acknowledged Friday he's under investigation for obstruction of justice for his ouster of FBI Director James Comey, and he suggested Rosenstein's partly to blame. Rosenstein wrote a memo outlining the case against Comey, and then picked Robert Mueller III to lead the Russia investigation. “I am being investigated for firing the FBI director by the man who told me to fire the FBI director! Witch Hunt,” Trump declared Friday in a tweet.

All of this makes Rosenstein a potential witness in Mueller's investigation. Rosenstein, according to news reports, has privately acknowledged he might need to do just that. The Washington Post reported Friday that Rosenstein sees no reason to recuse. “As the deputy attorney general has said numerous times, if there comes a point when he needs to recuse, he will. However, nothing has changed,” a Justice spokesman said in a statement.

Brand, meanwhile, has kept a low-profile at the U.S. Department of Justice since her May 18 confirmation by the U.S. Senate.

“Brand will face the tough task of insulating the investigation from the erratic and inappropriate behavior of President Trump,” Jack Goldsmith and Benjamin Wittes wrote Friday in a post at the Lawfare blog that looked at the possibility of Brand taking over for Rosenstein. “Such insulation is needed for the integrity of the investigation, so that any decisions it may reach about prosecution or exoneration have credibility. This task will require backbone—and a willingness not to last long in the job.”

Here's what to know about Brand, who could soon take the reins over Mueller's growing probe.

Brand is well-respected. Her confirmation process at the Senate was largely free of controversy. Though she was confirmed by a much smaller margin than Rosenstein, a bipartisan group of eight former attorneys general and deputy attorneys general wrote the Senate Judiciary Committee in support of her nomination. That included Alberto Gonzales, the former attorney general under President George W. Bush, and David Ogden, former deputy attorney general under President Barack Obama. Another letter, from former colleagues of Brand's, noted that “while many of us have profound disagreements with the Trump administration and its policies, we believe that [Brand] will perform her duties in the finest traditions of the Department of Justice—with honesty, integrity and respect for the rule of law.” Other letters of support for Brand came from conservative voices, including Charles Fried, the solicitor general under President Ronald Reagan and the National Fraternal Order of Police.

In 2006, Brand was recommended to be the top federal prosecutor in the Western District of Michigan. The proposal from Gonzales' chief of staff, D. Kyle Sampson, came as the Justice Department began to discuss removing several U.S. attorneys. Brand, 33 at the time, ultimately decided she wanted to stay in the Office of Legal Policy.

She has a deep background in regulatory issues. Brand spent the latter half of the Obama administration fighting federal agencies in court for the U.S. Chamber of Commerce before returning to the Justice Department this year. As the chamber's chief counsel for regulatory litigation—a new position created in 2011—she challenged Obama's recess appointments to the National Labor Relations Board and the U.S. Securities and Exchange Commission's rule requiring companies to disclose their use of minerals from war-torn regions of Africa.

Brand is a Big Law alumna. After leaving President George W. Bush's Justice Department, Brand joined the law firm Wilmer Cutler Pickering Hale and Dorr in 2008. In the firm's hiring announcement,

Diego M. Radzinschi

Wilmer Hale partner Jamie Gorelick praised Brand, a counsel at the firm, as a rising star in the legal profession. Gorelick is now representing Trump's son-in-law, Jared Kushner. Brand was at Wilmer from 2008 to 2011. Mueller joined the firm in 2014, so he and Brand did not overlap there.

“She was a star at Wilmer, and she's done an excellent job in every position she's held,” Gorelick said Friday.

Brand's husband, Jonathan Cohn, is a partner at Sidley Austin in Washington, a relationship that means she cannot participate “personally or substantially” in any matter that involves the firm or her husband's clients, according to her ethics agreement. Cohn is a member of the firm's commercial litigation and U.S. Supreme Court groups. Peter Keisler is the co-head of Sidley's Supreme Court team.

Brand shared her confirmation hearing with Rosenstein. The two lawyers appeared together before the Senate Judiciary Committee in March, when Sen. Chuck Grassley inquired about how Brand would transition from challenging the government to protecting its actions. “Just as when I was at a law firm, when I was at the Chamber of Commerce I had a client—the Chamber of Commerce,” Brand replied. “And as a litigator there, my job was to file lawsuits and file amicus briefs on behalf of that client. If I'm confirmed to this position, of course, I'll have a very different role. I'll have a different client.”

Brand's worked SCOTUS “murder boards.” At the Justice Department, she helped select and shepherd federal judges through the confirmation process. In September 2005, Brand, then assistant attorney general as the head of the DOJ's Office of Legal Policy, oversaw the mock hearings used to prepare John Roberts Jr. for his Senate confirmation hearings. Roberts participated in at least 10 so-called “murder boards,” lasting two to three hours each.

Photo: Diego M. Radzinschi/ALM

Brand also ran murder boards for Bush's second high court nominee, then-White House counsel Harriet Miers, who eventually withdrew her name, and her successor nominee—then-Judge Samuel Alito Jr. Brand was a law clerk for Supreme Court Justice Anthony Kennedy from 2002 to 2003. Her fellow Kennedy clerks included Brian Matsui, partner in Morrison & Foerster's appellate and Supreme Court practice; Igor Timofeyev, partner in Paul Hastings' litigation practice, and Kirkland & Ellis' Michael Williams, a litigation and appellate partner. The term was notable for Kennedy's majority opinion striking down Texas' criminal sodomy law, and Kennedy's dissent in Grutter v. Bollinger, which upheld affirmative action at the University of Michigan Law School.

Before joining the Justice Department, Brand served in the White House counsel's office under Bush. She helped draft the executive order creating the Office of Homeland Security, the precursor to the Department of Homeland Security, according to her profile in a Harvard Law School alumni publication. The title of that profile: “Committed to government service but not to big government.” She attended Harvard Law School from 1995-98.

Brand is deeply familiar with privacy and civil liberties. From 2012 until her confirmation, Brand was a member of the Privacy and Civil Liberties Oversight Board, an independent government agency that advises the executive branch. In a 2015 opinion column for The Hill, Brand stressed the importance of balancing civil liberties with robust, effective intelligence. “Contrary to the perception that foreign intelligence gathering by the United States is like the lawless Wild West, U.S. intelligence agencies are the most heavily regulated, transparent, and closely overseen of any country in the world,” she wrote. Just last year, she testified before the Senate Judiciary committee on the the National Security Agency's surveillance practices.

She began her career as an FBI intern. She started out as an honors intern at the bureau in 1996, according to her Senate questionnaire. She went on to work as a summer associate at Covington & Burling, Cooper, Carvin & Rosenthal and Simpson Thacher & Bartlett, and as a clerk for Fried when he was associate justice of the Supreme Judicial Court of Massachusetts.

Marcia Coyle, senior Washington correspondent, contributed to this report.