Republicans on the House Oversight and Government Reform Committee went after IRS Commissioner John Koskinen again Monday, while Democrats on the panel reserved much of their ire for Chairman Darrell Issa.

Issa, involved in a high-profile clash earlier this year with ranking member Elijah E. Cummings, D-Md., hammered Koskinen over the lost emails of Lois Lerner, the former IRS official at the center of the investigation, concluding his opening questions by telling the IRS commissioner, “I’ve lost my patience with you.”