Jessie K. Liu, the U.S. attorney for the District of Columbia who had been tapped to take the Justice Department’s No. 3 job, has withdrawn from consideration after Republican senators raised concerns about her past membership in a lawyers group that supported abortion rights and opposed the nomination of Samuel A. Alito Jr. to the Supreme Court.

The Trump administration signaled weeks ago that it would nominate Liu for the position of associate attorney general, in which she would oversee the department’s extensive civil litigation work. That nomination will not happen, because of her past role with the lawyers group, officials said Thursday.

The key Justice Department position has been difficult for the Trump administration to fill. The previous Senate-confirmed associate attorney general, Rachel Brand, left the post more than a year ago after just months on the job to take an executive position with Walmart.

A spokesman for Liu did not immediately respond to a request for comment.

Attorney General William P. Barr, in a statement Thursday, called Liu “one of the finest, most impressive people serving in the Department of Justice. She has been an outstanding United States Attorney and would have made an outstanding Associate Attorney General. I have zero doubt she would have faithfully executed my priorities and advanced my rule-of-law agenda.”

Barr said he was appointing her instead to lead the Attorney General’s Advisory Committee.

The reasons for the reversal stretch back more than a decade, when Liu was a member, and served as vice president, of the National Association of Women Lawyers.

“Unfortunately, a women’s lawyers professional organization that Jessie was affiliated with over a dozen years ago took certain controversial positions at the time which have now generated opposition to her nomination at the Senate Judiciary Committee,” said Justice Department spokeswoman Kerri Kupec.

The issue of her past involvement with the group did not surface during her confirmation to become U.S. attorney, and Liu is staying in that job, officials said.

Liu, 46, was confirmed in August 2017 to head the country’s largest U.S. attorney’s office, one that often oversees politically sensitive investigations of the executive and legislative branches.

Liu has been seen as a steadying presence at a U.S. attorney’s office where 300 attorneys have unique federal jurisdiction in the nation’s capital to prosecute local and federal crimes.

She reorganized an office where her recent predecessors were criticized for their handling of a drawn-out public corruption investigation of then-D.C. Mayor Vincent C. Gray (D), who was never charged but was voted out of office after prosecutors disclosed, in a pre-election news conference, that he was their target.

Liu’s highest-profile move as U.S. attorney came last month, when her office began to prosecute more defendants in the District for gun and drug crimes in federal rather than local court, as the city struggles with a 40 percent spike in homicides.

Liu, a graduate of Yale Law School, was an assistant U.S. attorney in the District from 2002 to 2006 before joining the Justice Department’s national security division and serving as a deputy assistant attorney general with the civil rights division until 2009.

She also worked at the Morrison & Foerster and Jenner & Block law firms.