As Jeb Bush’s older brother campaigned across Florida in his first bid for the White House, public rallies that the state’s governor and his deep political organization amassed made it clear they weren’t kidding about calling this “Bush Country.”

In the end, following a 36-day court battle over disputed ballots settled by the Supreme Court, this is the state that seated the 43rd president of the United States.

And when Jeb himself set out this year to seek the office that both his brother and father had held, an array of the Sunshine State’s Republican royalty lined up to help him. They had no idea, though, that they’d confront a national revolt against the party’s established leadership in the guise of a charismatic billionaire with a bully’s taunts for any possible rivals, dismissing them all in simple tweeted insults — Donald Trump’s monicker for Jeb Bush: “Low-energy.”

Yet now, a high-energy storm is brewing in hurricane alley. Now, it’s some of Florida’s longstanding Republican establishment that’s rebelling, raising a realistic possibility that the largest swing state, the one which might again tip the Electoral College, may well help seat the next president: Hillary Clinton.

Sally Bradshaw, who has campaigned for the Bush family since the 1980s and remains Jeb Bush’s closest political confidante, announced this week not only that she cannot support Trump — she also has withdrawn her voter registration as a Republican, going unaffiliated. And if Florida is close, she’ll vote for Clinton.

“This is a time when country has to take priority over political parties,” Bradshaw told CNN’s Jamie Gangel, a longtime Bush family whisperer. “This election cycle is a test,” Bradshaw said, calling Trump a narcissist, misogynist and bigot. “As much as I don’t want another four years of (President Barack) Obama’s policies, I can’t look my children in the eye and tell them I voted for Donald Trump.”

Jeb Bush too, among the early victims of Trump’s primary election successes, has made his own case against his party’s nominee well-known. Neither he nor the two President Bushes attended the convention that nominated Trump.

“While he has no doubt tapped into the anxiety so prevalent in the United States today, I do not believe Donald Trump reflects the principles or inclusive legacy of the Republican Party,” Bush wrote in The Washington Post before the conventions. “And I sincerely hope he doesn’t represent its future.”

Bush has stopped short of embracing Clinton: “I haven’t decided how I’ll vote in November — whether I’ll support the Libertarian ticket or write in a candidate.”

“It will not take many to tip the scale in Florida — three percent to five percent of Republicans who would normally vote in November,” J.M. “Mac” Stipanovich, a longtime Republican lobbyist and political strategist who opposes Trump, tells InsideSources — adding that he is trying to “persuade/shame others daily.”

“To me, a political party can stand the loss of a presidential election — heck, we’ve lost a lot of them — but you can’t stand the loss of your principles,’’ says Al Cardenas, a former Republican Party of Florida chairman who promoted Bush’s elections.

Cardenas suggests there are at least four places that any responsible Republican might be at this point: Embracing Trump and what he stands for; supporting him as preferable to Clinton; rejecting him outright as Bush and Mitt Romney have done; leaving the party, as Bradshaw and columnist George Will have done.

“I’m in this fifth category, I’m staying on the fence. I can’t support Donald Trump now — not because I don’t support him philosophically, I’m not supporting Donald Trump because I’m not convinced that he is fit to hold the office,’’ Cardenas says. “I’ve been waiting for him to show me, but that runway is getting shorter every week. I’ve been following him closely after the convention, but his behavior is getting so irrational that it’s compounded my concerns.’’

For the first time, this Republican says, he may have to “skip that line” on the presidential ballot.

The contest is “just very fluid,” says Susan MacManus, professor of political science at the University of South Florida, witnessing widespread concern about Trump among Florida’s political activists and elected officials. “When you think about Florida, this is one of the party’s success stories for broadening the base… Their fear is that all the inroads they’ve made in broadening the base are going out the window with the snap of the thumb of a Trump candidacy.”

Among those who’ve backed the Bushes in the past and stand ready to vote for Clinton if necessary, Stipanovich served as Florida director of the Reagan-Bush campaign in 1984, ran the campaign and office of Republican Gov. Bob Martinez and remains one of the state’s smartest political strategists. He wrote in an open letter in May: “We Republicans stand on the threshold of a fundamental moral test in the 2016 presidential election, a challenge so serious as to be existential.”

Trump, he wrote, “is a boor, a bully, a carnival barker and an embarrassment. Politically, by intent or instinct, he is a neo-fascist — a nativist, an ultranationalist, a racist, a misogynist, an anti-intellectual, a demagogue and a palingenetic (sorry) authoritarian to whom clings the odor of the political violence he encourages.”

Stipanovich makes the case that disaffected Republicans can swing Florida’s 29 electoral votes in a close race — and the average of public opinion polls in Florida before the parties’ conventions portrayed a dead-heat between Clinton and Trump.

“If Trump falls under 90 percent of Republicans, he loses Florida and the White House,” he says, “And I suspect Trump is correct — there is a secret vote, but not the one he anticipates.  I suspect there are Republicans who will not admit to voting for Hillary or helping her by abstention, but will do so.”

His own vote remains strategic: “I have not decided if I will vote for Hillary. Like Sally, it may depend on the circumstances.”

There are other public signs of private unrest in Bush Country.

Jorge Arrizurieta, a South Florida businessman long involved in Bush family and Republican Party fundraising who won a Bush 43 White House appointment to the Inter-American Development Bank, pointed to Jeb Bush’s essay in the Washington Post on his Twitter account and suggested there: “Don’t let anyone politically bully you into thinking not voting for Trump = voting for Hillary Nonsense.”

Ann Herberger, a South Florida fundraiser who has generated millions of dollars for the Bush family’s campaigns, tweeted this during the Democratic National Convention: “Brick by brick, issue by issue @HillaryClinton campaign is dismantling @realDonaldTrump like a surgeon. #DemsInPhilly

She also has retweeted a FiveThirtyEight map of what the nation would look like “if women refuse to vote for Trump.” It’s 50-state blue.

That map begins with a built-in structural advantage for Clinton. Eighteen states and the District of Columbia have voted Democratic in six of the last presidential elections — consistently since 1992. This includes electoral vote-rich states such as California, New York, Pennsylvania and Illinois. Among them: 242 electoral votes. If Clinton can hold these, she can claim the 270 needed with Florida alone.

Florida is the ultimate swing-state prize. Florida voted twice for Obama and twice for George W. Bush, once for Bill Clinton and once for George H.W. Bush.

Clinton introduced her running mate there, with Sen. Tim Kaine rolling out some Spanish in a state where 15 percent of voters are Hispanic. Longtime Rep. Ileana Ros-Lehtinen, who represents a majority-Hispanic Miami district where polling has found Clinton running well ahead of Trump, says she’ll vote for neither one.

Trump is campaigning in heavily Republican Jacksonville and swing-voting Daytona Beach this week, and tweeted this in the midst of CNN’s report of yet another Republican defection this week: “CNN will soon be the least trusted name in news if they continue to be the press shop for Hillary Clinton.”

Support in Florida is difficult to measure, as many voters there and elsewhere hold both of the major parties’ 2016 presidential nominees in disdain. “What you’ve got in both parties is an unknown portion, more than ever, of people who are not going to vote for their own candidate or go to the other side,” MacManus says. “As long as you have those kinds of circumstances, it’s very hard to poll.”

The most vocal protests from Bush County, however, are readily identifiable.

“I can tell you where it’s mostly coming from. It’s coming from the political activist and office holding class,” MacManus says. “They’ve worked their whole lives for certain principles and policies and they don’t want that erased… They don’t want that sort of tarnish on their record of achievement, which they’re very proud of.”

Editor’s Note: This story has been updated to include the comments from Al Cardenas.