"Oh, shut up": Maine Senate debate gets testy

Maine Republican Sen.

Susan Collins and her Democratic challenger Troy Jackson were sparring in a testy debate Thursday night when a protester loudly interrupted them.

"So this is obviously one of Troy's supporters," Collins said.

"Oh, shut up," Jackson shot back.

"I don't even know that kid." Why it matters: Collins and Jackson are competing in one of a handful of races that will determine the Senate majority.

The two have traded barbs in a series of tense debates, but this was the first time they sounded like children arguing on a playground.

Zoom in : At another point in the debate, Collins, who's been accused of not standing up to President Trump enough, was asked by a moderator to name a time when she opposed him and it changed the outcome.

"At one point, I had organized people to vote against Secretary Hegseth," she responded, referring to the Defense Secretary Pete Hegseth's confirmation.

"As you undoubtedly have read, at the very last minute one of our Republicans changed his mind.

Otherwise he would've been defeated for that job." Collins was talking about Sen.

Thom Tillis (R-N.C.), who went on to call his eventual decision to vote for Hegseth the "biggest regret of my career." "So that didn't change the outcome," the moderator said.