In June 2016, with the presidential campaign in full swing, former President Clinton boarded Ms. Lynch’s Justice Department plane on the tarmac in Phoenix. When the visit became public, it raised questions about her ability to oversee the investigation in an impartial manner. A report from the department’s inspector general later found that the brief meeting “was an error in judgment.” Ms. Lynch has said she viewed it as purely social.

As a former attorney general, Ms. Lynch, 60, was an attractive job candidate for many law firms. She was also coveted in an industry that has faced intensifying criticism for its lack of racial and gender diversity.

A recent report by the New York City Bar Association faulted top law firms for the “slow ascension to leadership and elevated attrition rates for attorneys of color and women.” The report found that after years of steady progress, the recruitment and advancement of minorities at big law firms had stagnated and even regressed.

Paul Weiss has a better record on that front than most big law firms. The nonprofit group Lawyers of Color found this year that Paul Weiss had the highest percentage of black lawyers — 8 percent — of the 400 firms it ranked.

But Paul Weiss has not been immune to criticism. This year, when the firm posted a photo on LinkedIn of a dozen new partners — all but one of them white men — it set off outrage on social media.

Ms. Lynch said Paul Weiss was a leader in focusing on diversity and took a “holistic approach to providing equal opportunity through the ranks.” She said that was important because at big law firms there was a tendency for “a lot of women and minority to move on to other professions.”

Since leaving office, she has taken a muted tone to criticizing the Trump administration. Delivering the commencement address at the Hofstra University Law School last week, she said the nation’s commitment to reason and the rule of law “now falls under daily attack from those we once trusted to uphold them.” By contrast, her immediate predecessor as attorney general, Eric H. Holder Jr., recently blasted Attorney General William Barr as being “not fit” to lead the Justice Department.

Ms. Lynch said she would rather stick to commenting on policy disagreements. She said in the interview that she was concerned that the Justice Department was backing away from its commitment to civil rights, especially when it comes to dealing with community policing.