Sen. Markwayne Mullin, President Trump’s nominee for DHS Secretary, faced a tense confirmation hearing amid questions about his past comments, aggressive behavior, and classified foreign travel as a House member.

Senators Rand Paul and Gary Peters pressed Mullin for details on “classified” trips and criticized his past remarks suggesting he understood or condoned violence against political opponents.

Mullin defended his record, saying he had nothing to hide, offered to discuss sensitive travel in a secure setting, and walked back earlier disparaging comments about immigration enforcement incidents.

Democrats also questioned his approach to ICE and his plans for DHS management, while Mullin promised a more collaborative and less micromanaged style than his predecessor, Kristi Noem, NBC News has reported.

The clashes highlight potential hurdles for Mullin’s confirmation, as he needs at least 50 Senate votes and faces opposition from Paul and questions from other committee members.