Stephen Mnuchin, Donald Trump's nominee for treasury secretary, is by no means the most controversial of Cabinet nominees the president-elect has put forward.

But tensions in the Senate confirmation hearing room were high Thursday — and they reached a boiling point before Mnuchin was even able to make his opening statement.

The tone was adversarial right from the beginning of the hearing. Sen. Orrin Hatch (R-Utah), the chairman of the committee, delivered an opening statement in which he attacked Democrats for what he sees as unfairly maligning nearly every nominee who has received a hearing so far.

“It is disappointing that we have taken this turn in the Senate, where the minority openly, and in so many words, is committed to obstructing nominees to positions across the board, in many cases knowing full well that they cannot prevent the outright confirmation of nominees at all,” Hatch said. “My colleagues sometimes are content to unfairly, and in some cases maliciously, malign more or less every nominee before they can assume their posts. I hope that's not true of our Senate Finance Committee members today.”

And from reports, that's a feeling he had after Wednesday's hearing for Trump's health and human services nominee, Rep. Tom Price (R-Ga.):

Democrats, of course, see it differently. Sen. Ron Wyden (Ore.), the ranking Democrat on the committee, got to make his opening statement after Hatch. And while Hatch spoke for about nine minutes, Wyden went on for nearly twice that long, detailing Mnuchin's history in the financial sector, accusing the nominee of trying to pay as little in taxes as possible, and mismanaging various funds he was in charge of, at the expense of middle-class workers.

That's when things got testy. Sen. Pat Roberts (R-Kan.) was given the opportunity to ask the first questions of the hearing before Mnuchin's opening statement. And after getting in one quick question about whether Mnuchin will work with Congress to prevent the IRS from targeting political groups, he turned to his colleagues on the Finance Committee.

“Senator Wyden, I've got a Valium pill here that you might want to take before the second round, just a suggestion, sir,” he said. Wyden briefly encouraged Roberts to get on with his questions.

“Mr. Mnuchin, from the distinguished ranking member's remarks, I understand you were in charge of the Great Recession,” Roberts pressed on, continuing to needle Wyden.

Then Sen. Sherrod Brown (D-Ohio) jumped into the conversation, and things got heated.

“Mr. Chairman, Mr. Chairman, I hope that that comment about Valium doesn't set the tone for 2017 in this committee,” he said. “I just, I like Sen. Roberts, I just can't quite believe that he would say that to a distinguished senator from Oregon.”

“I said that to the president of the United States at one point,” Roberts retorted.

Then things really got ugly.

The Senate has some pretty strict standards of decorum, particularly when it comes to treatment of fellow senators on the Senate floor and in hearings; Brown was clearly offended, while Roberts insisted he was just being funny.

It's impossible to say what the tone will be in the Finance Committee, or the Senate as a whole, in 2017 — after all, the new administration hasn't even taken power yet. But if the early minutes of Mnuchin's hearing are any indicator, we could be in for some very lively face-offs.