WASHINGTON — The “shackles” gone, Donald Trump stepped up his fierce attacks on his own party leaders Tuesday, promising to teach Republicans who oppose him a lesson and fight for the presidency “the way I want to.”

“I’m just tired of non-support” from leaders of the party he represents on the presidential ticket, Trump said Tuesday evening on Fox News Channel’s “The O’Reilly Factor.” He saved special ire for House Speaker Paul Ryan, who told Republicans Monday he’ll no longer campaign for Trump with four weeks to go before Election Day.

“I don’t want his support, I don’t care about his support,” Trump said. “I wouldn’t want to be in a foxhole with a lot of these people that I can tell you, including Ryan. By the way, including Ryan, especially Ryan.”

With his campaign foundering and little time to steady it, Trump reverted to the combative, divisive strategy that propelled him to victory in the GOP primary: Attack every critic — including fellow Republicans. Those close to Trump suggested it was “open season” on every detractor, regardless of party.

“It is so nice that the shackles have been taken off me and I can now fight for America the way I want to,” Trump said in a tweet that brought new concern — near panic in some cases — to a party trying to stave off an all-out civil war before Nov. 8.

In another series of tweets, the Republican nominee called Ryan “weak and ineffective,” Sen. John McCain “very foul-mouthed” and “disloyal” Republicans “far more difficult than Crooked Hillary.”

“They come at you from all sides,” Trump declared. “They don’t know how to win — I will teach them!”

At a night rally in Florida hours later, Trump made no mention of the apparent Republican civil war, instead training his fire on his Democratic opponent Hillary Clinton.

Rage against fellow Republicans from the face of the 2016 GOP exposed a party slipping from mere feuding into verbal warfare, with advance voting already underway in roughly half of the states. Polls suggest Trump is headed toward a loss of historic proportions if he doesn’t turn things around.

His scorched-earth approach, days after his sexually predatory language caught on tape triggered a mass Republican defection, threatened to alienate even more supporters.

“Fighting for the sake of fighting is not really very helpful,” former Trump adviser Barry Bennett said.

Trump has acknowledged the possibility of defeat in recent days, but on Tuesday he tried to shift the blame for his struggles on Republican defections and an election system that may be “rigged” against him. On Monday, he warned of potential voter fraud in heavily African-American Philadelphia, a claim for which there is no evidence but one that could challenge Americans’ faith in a fair democratic process.

At the same time, Trump’s campaign is considering whether to feature Bill Clinton accusers at his upcoming rallies. Trump shocked the political world before Sunday’s debate by appearing with several women who had accused the former president of sexual impropriety decades earlier.

The aggressive shift is in line with the philosophy of recently hired campaign chairman Steve Bannon, whose conservative website has long fueled attacks on Republican leaders and perpetuated popular conservative conspiracy theories.

The approach has done little to endear Trump to anxious party leaders. At least 40 Republican senators and congressmen have revoked their support for the embattled Republican nominee — with nearly 30 of them urging him to quit the race altogether.

Ryan, in a Monday conference call with congressional Republicans, said he would no longer campaign with Trump. He said he would focus instead on ensuring Clinton doesn’t get a “blank check” with a Democratic-controlled Congress, all but conceding that Trump would lose the presidential contest.

Trump’s running mate Mike Pence said in an interview with NBC Tuesday that he was “disappointed” by the defections and “respectfully” disagreed with Ryan.

Yet Trump’s aggressive shift is popular among his most loyal supporters, who continue to flock to his rallies by the thousands.

Allison Ellis, 30, deemed Ryan “a traitor” and shrugged off Trump’s sexually aggressive comments in the 2005 video. She pointed at Democrat Hillary Clinton’s shortcomings.

“I have daughters and I don’t like what he said but I also wouldn’t want to be held responsible for everything I said 11 years ago,” Ellis said at Trump’s Panama City Beach, Florida, rally. “And it’s nothing compared to what she did — she should be in jail.”

But some of Trump’s supporters admitted their confidence was shaken.

“I still think he can do it, but he has to play mistake-free the rest of the way,” said Mike Novoret, 59. “If something else comes up, he’s toast.”

At a rally in Newton, Iowa, Pence received multiple standing ovations and was thanked at one point for sticking with Trump.

“You . . . just got my respect for not jumping and bailing out on Donald Trump,” the questioner said.

Another woman told Pence she was concerned about widespread voter fraud and warned that, if Clinton wins, “I am ready for a revolution.”

“Don’t say that,” Pence responded.

As the GOP battled itself, Clinton focused on climate change in swing state Florida alongside former Vice President Al Gore.

Gore, whose 2006 documentary “An Inconvenient Truth” focused on global warming, said Clinton would “make solving the climate crisis a top national priority.”

Trump’s campaign released a new ad that focuses on Clinton’s recent bout with pneumonia. The ad features images of masked gunmen and nuclear weapons as a sick Clinton stumbles toward a vehicle.

And at the rally in Panama City Beach, Trump declared that hacked emails released by WikiLeaks on Tuesday showed collusion between the Clinton campaign and the Justice Department during an investigation into the former secretary of state’s email server.

The evidence does indicate there was communication between the two about a court hearing date. But such dates are not inside information. They would have been publicly posted in advance on the court’s docket.

The emails show that in May 2015, Clinton spokesman Brian Fallon alerted other staffers that the Justice Department was proposing to publish Clinton’s work-related emails by January in response to requests by news organizations. Fallon, a former Justice Department spokesman, wrote that unspecified “DOJ folks” told him there was a court hearing planned soon in the case.

The name and email address of the person who shared the information with Fallon had been deleted.

Trump also declared that the Clinton transcripts released by WikiLeaks show evidence that she is a “vessel of corrupt global establishment” who is “ruining the sovereignty of our nation” by pushing for open borders and global governance.

Lemire reported from Panama City Beach, Florida, and Colvin from New York. Associated Press writers Eric Tucker in Washington and Brian Slodysko in Newton, Iowa, contributed to this report.