The Trump administration has not yet announced a nominee to be assistant attorney general for the civil rights division. But the administration has installed two deputies as acting chiefs to run it in the interim.

One new deputy is Thomas Wheeler, who was general counsel to Vice President Mike Pence when Mr. Pence was the governor of Indiana. According to Mr. Wheeler’s cached biography on the website of his former law firm, he has extensive experience defending schools and municipalities against employment discrimination lawsuits.

The other deputy, John M. Gore, helped with his law firm’s defense of several states’ redistricting plans, and was among the lawyers who represented Florida when it was sued over a disputed attempt to purge its voter rolls close to an election. He also sought to get the University of North Carolina dropped from a lawsuit challenging a state law barring transgender students from using bathrooms that correspond with their gender identities.

Ms. Clarke expressed “concerns” about both men and sought to link the delayed hearings to Mr. Trump’s baseless claim at a meeting on Monday with congressional leaders that millions of unauthorized immigrants illegally voted for Hillary Clinton in November’s election. She called that claim “an invitation for voter suppression tactics to be put on the books.”

Her attack came as Democrats forced a one-week delay on a Senate Judiciary Committee vote on Mr. Sessions’s confirmation. Ultimately, Mr. Sessions appears almost certain to be confirmed by the Senate, where he has served as a Republican from Alabama since 1997.

Democrats have made Mr. Sessions’s civil rights record in Alabama and Washington one of their main points of attack, reviving questions that have dogged him for 30 years about his racial attitudes and his handling of civil rights litigation.