Sen. Tim Kaine said he pushed Defense Secretary-nominee Pete Hegseth about infidelity and sexual misconduct in a hearing last week because he believed it was the only way to get Republicans to consider voting against him.

Speaking Sunday on CBS’ “Face the Nation,” Kaine (D-Va.) said: “My observation of my Republican colleagues is the only reason they ever vote no on a nominee is either a belief of gross incompetence in terms of qualifications or serious character deficit.”

As an example, Kaine cited the case of then-Rep. Matt Gaetz (R-Fla.), whose chances to be President-elect Donald Trump’s attorney general were quickly scuttled by personal scandal.

In Hegseth’s Senate hearing Tuesday, Kaine asked at one point: “You acknowledge you cheated on your wife and that you cheated on the woman by whom you had just fathered a child?”

The Virginia senator also raised concerns about a 2017 incident in California in which a woman accused Hegseth of sexual assault. “I know in my instance it was a false claim,” Hegseth said in response.

On Sunday, Kaine said Senate Democrats had divvied up topics to address since Hegseth wouldn’t meet with them. He also said he thought the questioning was effective.

“I think overall, in the hearing, we put a lot of material on the table for folks to consider,” he told host Margaret Brennan.

Those questions don’t seem to created much doubt about his nomination among Senate Republicans, who have a 53-47 majority. In fact, Sen. Joni Ernst (R-Iowa) endorsed Hegseth after the hearing, saying: “Our next commander in chief selected Pete Hegseth to serve in this role, and after our conversations, hearing from Iowans, and doing my job as a United States senator, I will support President Trump’s pick for secretary of Defense.”

Regardless. Kaine still found much not to like about the nominee.

“I believe he would be a very dangerous secretary of Defense,” Kaine said Sunday.