Mr. Koskinen "is a man of the highest integrity," said White House deputy press secretary Eric Schultz, who called him "the right person to lead this agency."
Rep. Jason Chaffetz, Utah Republican and chairman of the House Committee on Oversight and Government Affairs, made his request Monday in a letter to Mr. Obama. He argued Mr. Koskinen has repeatedly "obstructed" congressional probes into the agency's political targeting of taxpayers, and that the president vowed in 2013 to "work hand-in-hand with Congress to fix the problem."
Mr. Chaffetz said that Mr. Koskinen, in more than two years in the job, has obstructed congressional investigations by failing to testify truthfully, comply with subpoenas and preserve as many as 24,000 emails related to congressional investigations.
Republican Reps. Ron Desantis of Florida and Jim Jordan of Ohio also said in an op-ed Monday in the Wall Street Journal that they'd try to impeach Mr. Koskinen if the president doesn't fire him.