The Obama administration circled the wagons around Hillary Clinton on Tuesday, with Attorney General Loretta E. Lynch refusing to detail why she didn’t pursue criminal charges against the former secretary and the State Department going to bat for her, saying she shouldn’t have to testify under oath about her secret email account.

Facing irate Republicans on Capitol Hill, Ms. Lynch repeatedly passed the buck to others in the Justice Department, saying that while she announced she wouldn’t pursue charges against Mrs. Clinton, the decision was made by the FBIand career prosecutors and she had no public thoughts on the matter.

She said refusing to divulge details of her decision protected her employees from political pressure, but Republicans said she was the one engaging in politics by protecting the Clintons as repayment for having been appointed as a prosecutor by President Bill Clinton.

Ms. Lynch said she decided, even before her ill-timed meeting with Mr. Clinton at a Phoenix airport, that she would accept whatever recommendation the FBI would make about prosecuting Mrs. Clinton.