WASHINGTON—A key witness in the contentious Senate confirmation of Defense Secretary Pete Hegseth was assured by Sen. Thom Tillis (R., N.C.) that her sworn statement would carry weight in last week’s vote and could convince Republican senators to oppose the nominee,

The North Carolina Republican said he did his “due diligence” and deferred to the Senate Armed Services Committee endorsement.

North Carolina Sen. Thom Tillis told Pete Hegseth’s former sister-in-law that a sworn statement about his alleged alcohol abuse and abuse of his second wife could convince senators—himself included—to oppose Hegseth’s confirmation as secretary of defense,