Watch full replay of second presidential debate between Trump, Clinton

Republican presidential nominee Donald Trump and Democratic presidential nominee former Secretary of State Hillary Clinton appear on stage during the town hall debate at Washington University on October 9, 2016. (Getty Images)

ST. LOUIS – Politics in America changed Sunday night.

The once sacred tradition of a presidential debate — where candidates typically trade barbs over their vision of the country’s future — exploded into something quite chilling.

The Republican nominee seemingly dismissed the significance of the vulgar language he used toward women a decade ago, apologizing for his conduct but repeatedly saying his remarks were just “locker room talk.”

With Hillary Clinton’s husband and daughter watching from the audience, Donald Trump lashed into Bill Clinton’s infidelities, calling him “abusive.” Trump said he would appoint a special prosecutor as president to investigate her — and even threatened that she would be jailed under his administration.

Clinton didn’t take the bait. She repeated First Lady Michelle Obama’s philosophy articulated at the Democratic convention: “When they go low, we go high.”

But Clinton made clear that her trouble with Trump goes beyond the partisan clash typical of a presidential campaign. She said she spent much of the past 48 hours thinking about the video that shows Trump making lewd and sexually aggressive remarks about women. She said that she had differed before with Republicans over policy.

“I never questioned their fitness to serve,” she said. “Donald Trump is different.”

Pacing the stage

Trump paced the stage for much of the debate, which was moderated by CNN’s Anderson Cooper and ABC’s Martha Raddatz. He had trouble standing still while Clinton spoke, sometimes appearing in her camera shot.

He lost his composure at one point after a fierce exchange with Clinton about her emails. He accused the moderators of not bringing up the question of her private email server, though the question came from Raddatz.

“Nice, one on three” Trump said, insinuating that the moderators were biased against him.

Trump’s performance and willingness to use every single tool at his disposal, from Clinton scandals to outlining his stark vision of a country in crisis, could electrify his loyal base voters. But the question is whether his stern demeanor, prowling stage presence and vow to prosecute Clinton if elected will help him broaden that voting base in a way that would help him catch up to Clinton’s lead in battleground states and in the national picture.

Hours earlier, Trump made a surprise appearance with women who have in the past accused Bill Clinton of inappropriate sexual activity. The women later attended the debate as members of the audience.

During the debate, Trump insisted he had not approached women without their consent but said he was “embarrassed” by the tape. He constantly tried to redivert the conversation even when challenged by CNN’s Anderson Cooper to his plans to “Make America Great Again,” saying he would go hard after ISIS for example.

Clinton said she had been thinking very carefully about the tape.

“Yes, this is who Donald Trump is,” Clinton said. “This is who Donald Trump is but the question our country must answer is this is not who we are.”