Donald Trump ventured into new political territory on Friday when he told supporters in Colorado Springs that his opponent, Hillary Clinton, should be thrown in jail.

“I’ve been saying, ‘Let’s just beat her on November 8th.’ But you know what? I’m starting to agree with you!” Trump said to a crowd that was yelling, “Lock her up! Lock her up!”

He also promised “no more Mr. Nice Guy,” for anybody who had been under a mistaken impression on that score.

“I’m taking the gloves off. Just remember this, Trump is going to be no more Mr. Nice Guy. Tell Hillary I’m not going to be nice anymore, are you ready?” he said.

The “Lock her up!” chant first rang out among Trump supporters at last week’s Republican National Convention, when New Jersey Gov. Chris Christie, a former federal prosecutor, ran down a list of Clinton’s alleged misdeeds as secretary of state.

At first, Trump himself responded to those cries by trying to tamp down the pitchfork mob enthusiasm. “Let’s defeat her in November,” he told the audience during his major convention speech. By this Friday, however, Trump had changed his mind.

For a major party’s presidential nominee to suggest that his chief opponent should be incarcerated appears to have no precedent over the last century of U.S. political campaigns. But that’s nothing unusual for Trump.

He broke new ground earlier this week when he publicly encouraged Russia to hack Clinton’s emails and publish their contents. The remarks prompted a swift public backlash from experts in national security and cyberwarfare. Trump later claimed that he was only joking.

Friday’s comments came at a rally during which Trump also delivered a number of seemingly off-the-cuff tirades against his perceived enemies. On this day, they included the fire marshal in charge of safety at the event, whom Trump accused of needlessly keeping people out of the 1,600-person University of Colorado auditorium.

“I’m not a fan,” Trump said of the unnamed public safety officer. “He’s probably a Democrat, a guy that doesn’t get it.”

Thank you Colorado Springs. Get out & VOTE #TrumpPence16 in November! pic.twitter.com/wK02fWzJey — Donald J. Trump (@realDonaldTrump) July 29, 2016

As for other foes revealed to him during the Democratic National Convention, Trump said, “I’m gonna hit them! Obviously I’m talking about with my verbal. Maybe a tweet. But I’m gonna hit em hard!”

For much of the speech, the GOP nominee fixated on a campaign ad from Hillary Clinton’s team, which features a clip of Trump mocking a disabled journalist and another of him ridiculing Fox News host Megyn Kelly.

“I spend so much money on working with disabled, making my buildings accessible. Millions and millions!” Trump said. “I spend millions of dollars a year on ramps and ‘Get rid of the stairs’ and different kinds of elevators.”

As an owner and manager of commercial properties, Trump is required to provide accommodations for people under the 1990 Americans With Disabilities Act. It was unclear exactly what, if anything, he has done above and beyond the law to support those with disabilities.

A spokeswoman for the Trump campaign did not respond to questions from HuffPost about Trump’s compliance with the ADA.

The only rough patch of the afternoon came when Trump seemed to prematurely blame Colorado voters, should he lose the general election in November. If “we don’t make it,” Trump said, it would be “because you people get lazy and don’t vote.”

Still, his crowd was with him, boasts and threats and all. “I have the best temperament of anybody that’s ever run for the office of president,” Trump said.

Editor’s note: Donald Trump regularly incites political violence and is a serial liar, rampant xenophobe, racist, misogynist and birther who has repeatedly pledged to ban all Muslims ― 1.6 billion members of an entire religion ― from entering the U.S.