Sen. James Lankford plans to become the top Republican on the Senate Homeland Security and Governmental Affairs Committee in the next Congress, positioning him to play a central role as Democrats prepare to scrutinize the Trump administration.

The Oklahoma Republican said he expects to work with Sen. Maggie Hassan of New Hampshire, who is set to chair the panel under the incoming Democratic majority. Both senators are expected to take their positions in keeping with their parties’ customary deference to seniority.

Lankford said the committee can work across party lines and has a responsibility to conduct oversight of the federal government. But he also signaled that he would challenge investigations he believes go too far.

“As the only Committee with broad oversight and subpoena authority across the federal government, we have an important responsibility to ask hard questions, get answers, and make sure government is working as it should,” Lankford said in a statement. “However, the job of any Ranking Member is to also push back on a majority that goes too far.”

He also defended the work of Department of Homeland Security personnel, saying their efforts should not be hindered by partisan politics. “Oversight is responsible, but obstruction is unacceptable,” he said.

The committee is the Senate’s primary oversight panel, and Hassan is expected to examine immigration enforcement tactics used by the Department of Homeland Security under President Donald Trump.

This week, Hassan called on former DHS official Corey Lewandowski to provide all records related to contracting during his time at the agency. She also asked him to preserve relevant records as she outlined her intention to use the committee’s investigative powers.

“I intend to use the Committee’s full authorities—including where necessary compulsory process—to expose corruption and waste,” Hassan wrote to Lewandowski. “I therefore renew my request that you preserve all relevant records.”

The coming leadership change sets up a test of how much common ground the two senators can find on oversight, even as they enter their roles with different priorities for the committee’s investigations.