The tension that has simmered in the Republican Party for years -- shutting down the government and nearly bringing the nation to default -- escalated into an outright civil war Tuesday.
The conflict not only threatens the party's ability to make any realistic attempt at reclaiming the White House next month, but also previews the conflicts and divides that could consume the GOP for years to come if Trump loses.
On one side is Donald Trump, who spent much of Tuesday lashing out on social media at his GOP foes, such as Speaker Paul Ryan and Sen. John McCain, and lamenting the lack of party unity. He's backed by conservative lawmakers including Iowa Rep. Steve King and the throngs of loyal supporters who attend his rallies, including the one here in Panama City, Florida, Tuesday, where he renewed his call for a government investigation into his opponent, Hillary Clinton.
On the other side is Ryan, who is devoting the full resources of his stature to maintaining a congressional majority. That dominance of Capitol Hill is suddenly threatened -- and not just in the Senate, where there are many competitive races, but also in the House, where the GOP majority was considered untouchable until recently.
The infighting -- sparked by the release Friday of a 2005 video depicting Trump describing women in vulgar and sexually aggressive terms -- isn't likely to ease in the 27 days before Election Day. Trump made clear Tuesday that if he loses in November, he won't go down quietly -- or alone.
He began the day with a series of shots -- taken over Twitter -- at Ryan, saying it's hard to do well when the speaker isn't supportive. He followed up about an hour later calling Ryan a "weak and ineffective leader."
And nearly two hours after that, Trump posed his most explosive tweet of the day.
'Shackles have been taken off me'
"It is so nice that the shackles have been taken off me and I can now fight for America the way I want to," he said.
Trump's turn on his own party may seem counterproductive -- it hardly allows him to improve his chances of catching Clinton. But it does allow him the satisfaction of vengeance against party leaders he believes have never treated him fairly since his stunning outsider campaign captured the nomination earlier this year.
And by blaming Republican leaders for their failure to wholeheartedly endorse his campaign, Trump also opens up the possibility of a face-saving excuse if he crashes to defeat in November.
But the cost to the Republican Party of Trump's burn-it-down-around-him strategy is already high, could become more extreme and potentially leave the GOP badly damaged long after he has left the political scene.
To begin with, the estrangement between Trump and the party leaders is blowing open a gaping split between the party's grass roots and its establishment leaders that Republican National Committee Chairman Reince Priebus and others worked so hard to bridge over the summer.
It is a divide that will be hard to overcome if Trump loses the election. Forging unity could be impossible if hordes of Trump voters blame party leaders for the defeat of a man who electrified the grass roots supporters in a way no other Republican has managed in decades.
King, the Iowa Republican congressman, warned Tuesday that a purge of party elites might be necessary, saying "the establishment wing of the party could simply be amputated out in this effort that's going on right now."
"They've gone so far out on this limb," King said on the Laura Ingraham radio show.
The meltdown in the GOP is the culmination of forces that have been building for years. Intense antipathy towards congressional leaders over their failure to more forcefully oppose President Barack Obama gave rise to the Tea Party and sent waves of anti-establishment lawmakers to Washington in successive elections.
Trump's adoption of a factually-challenged style of campaigning would have been impossible without the power of conservative media that has been building for decades and is now fused with the GOP presidential ticket through the role of Stephen Bannon, the head of Breitbart News, who serves as the CEO of the Trump campaign.
Trump's turn against his own party could also reverberate in down-ballot races. Republicans have long known that their hold on the Senate was tenuous -- whoever ran at the top of their ticket -- but Trump's slumping poll numbers now threaten to drag down vulnerable incumbents too.
Cutting into GOP majority
At the very least, a Trump implosion that cuts deeply into Ryan's majority could complicate the Speaker's already tough task of corralling his volatile majority coalition. If an anti-Trump landslide sweeps away House GOP members in more moderate districts, it could hand more relative power to the ultra-conservative Freedom Caucus and give him the same kinds of fits that it imposed on John Boehner, his predecessor.
The dilemma is especially difficult for Republican senators running for re-election. Some are rejecting Trump because of revulsion at his remarks among more moderate voters. But at the same time, they risk alienating Trump supporters in states's where the former reality star racked up high margins in the primary race.
New Hampshire Sen. Kelly Ayotte fits into this category and her desperate effort to walk the fine line between condemning and embracing Trump during this election has become a symbol of the wider GOP conundrum. Ayotte finally said she could not vote for Trump after the video emerged on Friday.
But another star of the GOP, Florida Sen. Marco Rubio, said Tuesday he's not yet ready to back away from Trump. Rubio looks certain to need Trump voters to maintain his narrow lead in his re-election race. But at the same time, if more explosive video emerges about Trump, Rubio, who has presidential ambitions in his future, risks being tarnished by association with the Republican nominee.
Another lawmaker in a tough re-election race who is hedging his bets is North Carolina GOP Sen. Richard Burr, who said that while Trump's comments were "indefensible," he still plans to support him.
Risks for Clinton
For her part, the turmoil consuming the GOP would seem to provide a substantial boost to Clinton's White House bid. An NBC News/Wall Street Journal poll released Tuesday found the Democratic nominee enjoying a 9-point lead among likely voters in a four-way race.
But her aides caution against excessive optimism. There's concern inside the campaign that an increasingly negative race -- which could only become darker in the days ahead -- could turn off voters and make them less likely to show up at the polls. In that instance, a lower turnout could create an advantage for Trump.
"This seems to be their strategy, disgust everyone with our democratic dialogue so that they won't come out to the polls," John Podesta, Clinton's campaign chairman, told reporters Tuesday. "I think it is very unbecoming a presidential candidate."
Clinton said as much herself during an interview with a Florida radio station Tuesday.
"Despite all of the terrible things (Trump) has said and done, he is still trying to win this election," she said. "And we cannot be complacent, we cannot rest."