Donald Trump started attacking members of his own party in a series of tweets Tuesday after many Republicans rescinded their support for the presidential nominee. The Fix's Chris Cillizza weighs in on the unprecedented unraveling of the GOP. (Jayne Orenstein/The Washington Post)

Donald Trump started attacking members of his own party in a series of tweets Tuesday after many Republicans rescinded their support for the presidential nominee. The Fix's Chris Cillizza weighs in on the unprecedented unraveling of the GOP. (Jayne Orenstein/The Washington Post)

Donald Trump declared war on the Republican establishment Tuesday, lashing out at House Speaker Paul D. Ryan (Wis.), Sen. John McCain (Ariz.) and other GOP elected officials as his supporters geared up to join the fight amid extraordinary turmoil within the party just four weeks before Election Day.

One day after Ryan announced he would no longer campaign on Trump’s behalf, the GOP nominee said as part of a barrage of tweets that the top-ranking Republican is “weak and ineffective” and is providing “zero support” for his candidacy. Trump also declared that “the shackles have been taken off” him, liberating him to “fight for America the way I want to.”

Trump called McCain “foul-mouthed” and accused him with no evidence of once begging for his support. McCain, the party’s 2008 presidential nominee, pulled his endorsement following a Friday Washington Post report about a 2005 video in which Trump is heard making vulgar comments about forcing himself on women sexually.

“I wouldn’t want to be in a foxhole with a lot of these people, that I can tell you . . . especially Ryan,” Trump said in an interview with Fox News Channel. He said if he is elected president, Ryan might be “in a different position.”

In perhaps the most piercing insult, Trump said his party is harder to deal with than even Democratic rival Hillary Clinton, whom conservatives loathe. Yet he also released a new TV ad featuring footage of Clinton coughing and stumbling during a recent bout with pneumonia — signaling that few issues are out of bounds for his scorched-earth campaign.

In the wake of a new Washington Post report showing Republican presidential nominee Donald Trump speaking in very lewd terms about women in 2005, some Republicans are calling for Trump to step down as nominee. (Thomas Johnson/The Washington Post)

“Disloyal R’s are far more difficult than Crooked Hillary,” he wrote for his more than 12 million followers on Twitter, his preferred platform for picking fights. “They come at you from all sides. They don’t know how to win — I will teach them!”

By backing away from Trump, Ryan and his allies were hoping to insulate themselves and their majorities on Capitol Hill from the baggage weighing down the nominee’s flagging campaign. For many, the breaking point was the 2005 video.

But they are suddenly dealing with another problem: an impulsive and bellicose businessman with an army of loyal supporters willing to exact retribution against elected officials they feel have abandoned them. The rift could have profound ramifications for the Republican Party as a whole, shattering any sense of unity and jeopardizing its chances of holding onto the Senate and even, potentially, the House.

[The GOP tumbles toward anarchy: ‘It’s every person for himself or herself]

Trump’s barbs left some backers unsettled, including Ben Carson, the retired neurosurgeon who has been a Trump booster for months and an informal adviser.

“Dr. Carson has been unwavering in his support but the last 24 hours have made that support very difficult to maintain,” Carson adviser Armstrong Williams said in a statement.

Carson said in a brief interview that Trump “would be wise to praise Ryan rather than be at war with him. I keep trying to emphasize to him that the issues are where you win.”

1 of 28 Full Screen Autoplay Close Skip Ad × Here are some of the Republicans who cut ties with Trump after lewd remarks View Photos Following a Friday report by The Washington Post on a 2005 video of the GOP presidential nominee, various Republicans have said they no longer plan to vote for him and some call for him to drop out. Caption Following a Friday report by The Washington Post on a 2005 video of the GOP presidential nominee, various Republicans have said they no longer plan to vote for him and some call for him to drop out. Sen. John McCain Sen. John McCain (R-Ariz.) joined the cavalcade of Republicans withdrawing their support for Trump. “There are no excuses for Donald Trump’s offensive and demeaning comments in the just released video; no woman should ever be victimized by this kind of inappropriate behavior. He alone bears the burden of his conduct and alone should suffer the consequences,” McCain said in a statement. Susan Walsh/AP Buy Photo Wait 1 second to continue.

But many others rallied around Trump, including the Republican National Committee. Its chairman, Reince Priebus, was in close touch all day with Trump advisers and RNC strategist Sean Spicer was at Trump Tower in Manhattan.

Mica Mosbacher, a Trump fundraiser and surrogate, said she was invited to a fundraiser next week for Ryan’s joint fundraising committee but is not going to attend or contribute because of the way Ryan has treated Trump.

“I don’t feel that Ryan is supporting our nominee and being a team player,” said Mosbacher, who is vowing not to give financial backing to Republicans who have crossed Trump.

Diana Orrock, a Republican National Committeewoman from Nevada, said she will not vote for Republicans who have pulled their support for Trump — including Rep. Joe Heck (Nev.), who is running for a seat that is critical in the battle for the Senate majority.

“I think they have really irritated a lot of Trump supporters,” Orrock said of Heck and Rep. Cresent Hardy (R-Nev.), who also rescinded his endorsement.

Former House speaker Newt Gingrich, a Trump ally, said Trump should “use the enormous power of social media” to mount a pressure campaign on wavering Republicans.

“It’s time for him to send targeted messages to each district and state and have Republican voters ask their candidates: ‘Are you going to help us defeat Hillary Clinton?’ And Trump should make it clear that the side effect of not helping Trump is electing Hillary Clinton.”

Trump spokeswoman Katrina Pierson tweeted Monday that she could not keep her mobile phone charged “due to the mass volume of texts from people” who plan to vote for Trump but not for other Republicans on the ballot.

[Trump’s truest believers start to worry: ‘You could easily lose’]

Ryan said Monday that he would no longer defend or campaign with Trump. Dozens of other Republican elected officials have gone even further, calling on Trump to leave the race in the wake of the 2005 video.

“Paul Ryan is focusing the next month on defeating Democrats, and all Republicans running for office should probably do the same,” Ryan spokesman Brendan Buck said in a statement responding to Trump’s attacks Tuesday.

Trump began his Twitter attacks Tuesday morning in New York before jetting off to raise money in Texas and to host an evening rally in Panama City Beach, Fla. At a San Antonio fundraising event, Trump tore into Ryan, whom he accused of “total disloyalty to the party.”

“I think they forgot that there was an election because something happened in the last month where you didn’t see them, right?” Trump said of prominent Republicans who have not campaigned for him, according to audio of the fundraiser obtained by the Texas Tribune. “You didn’t see them. I said: ‘Why aren’t they on the shows? Why aren’t they all over the place?’ ”

Trump campaign spokesman Jason Miller said the campaign was not preoccupied over whether congressional leadership is with the nominee.

“Mr. Trump’s campaign has never been driven or fueled by Washington. It’s always been driven by the grass roots and it will continue to be,” Miller said. “What we want is everyone who wants to defeat Hillary Clinton to be on board. Anyone who’s concerned about the direction of the country.”

A Ryan confidant said the House speaker — the highest-ranking Republican in the country — is trying to strike a careful balance by turning away from Trump but not officially withdrawing his endorsement.

“He’s threading a lot of needles here,” said the confidant, who spoke on the condition of anonymity in order to talk candidly. “He wanted to make a clean break with Trump. So saying ‘I won’t defend him and won’t campaign with him’ was his way of making a break. He was so repulsed by the tape. But there are still a lot of members in the conference who don’t want to be at war with Trump’s voters in their district.”

Speaking on his radio show Tuesday, popular conservative talk-show host Rush Limbaugh said: “The Republican Party has sided with its donors and its lobbyists, and this is why we’re where we are. The Republican Party is in a predicament that it made itself. It made its own bed, and now they don’t want to lay in it. Now they want to run from the bed that they made.”

Some Republicans have agonized over how to deal with Trump in the final weeks of the race. Sen. Marco Rubio (Fla.), who ran against Trump in the GOP primaries and is running for reelection in a key battleground state, issued a statement Tuesday saying he continues to support the nominee, whom he once called “dangerous” and a “con man.”

“I disagree with him on many things, but I disagree with his opponent on virtually everything,” Rubio said. “I wish we had better choices for President. But I do not want Hillary Clinton to be our next President. And therefore my position has not changed.”

The sentiment that Trump is far from ideal but is better than the only realistic alternative is one many of his backers are clinging to as justification for maintaining their support.

“You don’t go after somebody who is, as Ronald Reagan would say, your 80 percent friend. What you do is stand with them,” Rep. Marsha Blackburn (R-Tenn.) said in an interview with Fox Business Network. “And it is not helpful to have this kind of drama going on. What you need to do is say we have a binary choice.”

Democrats on Tuesday continued their fierce criticism of Trump’s lewd comments about women. White House press secretary Josh Earnest said that President Obama found the 2005 video “repugnant” and that “there has been a pretty clear statement by people all along the ideological spectrum that those statements constituted sexual assault.”

Campaigning for Clinton in Greensboro, N.C., Obama called Republican officials out for the way they have dealt with Trump.

“They can’t bring themselves to say, ‘I can’t endorse this guy,’ ” Obama said. Of those who did pull their endorsements, the president added: “Why’d it take so long for some of them to finally walk away? We saw this coming.”

[Trump’s truest believers start to worry: ‘You could easily lose’]

A friend of Ryan, who was granted anonymity to speak freely, said the speaker didn’t rush into his Monday decision, but was deliberative and thoughtful. In the end, there was no way to make everyone happy.

“He’s just in a hard place, and Trump is recognizing that he’s in a hard place and pushing the lever harder,” the friend said.

David Weigel in Washington and David Nakamura in Greensboro, N.C., contributed to this report.