The GOP has weathered tough elections only to rapidly emerge stronger – but can it survive if the millions Trump has brought into the fold go back into hiding?

As the Rolling Stones’ You Can’t Always Get What You Want boomed over loudspeakers after Donald Trump’s rally in Kissimmee, Florida, on Thursday night, an elderly spectator walked by the media enclosure. “Traitor! Traitor! You’re guilty of treason, all of you!” he shouted, before giving journalists the middle finger. “Up yours! Pack your bags and get out of here!”

He was far from alone in asserting that Trump’s recent mishaps – clashing with the parents of a fallen US army captain, hinting at the assassination of Hillary Clinton – and his dismal poll numbers were the product of a liberal media conspiracy. Their faith unshaken, the Republican nominee’s superfans cheered him with religious fervor and, when he lambasted the media, turned to boo with no less passion.

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As the Washington pundits and pollsters wrote them off, there was a sense of circling the wagons. But hours earlier, Trump had made a rare admission. “At the end, it’s either going to work or I’m going to, you know, I’m going to have a very, very nice long vacation,” he told CNBC. If, as every recent survey suggests, he does indeed suffer defeat, it raises the question of what will happen to the 13.3 million people who voted for him in the Republican primaries and whether, ultimately, Trumpism can survive Trump.

Several supporters at Thursday’s rally – where raucous crowds punched the air and chanted “Lock her up!” and “Liar! Liar!” – told the Guardian they believed that he would only lose the election if it were rigged. Should that happen, some said they intended to remain engaged in politics, but more likely with a third party than with the Republicans – especially if that party were to revert to establishment figures such as Jeb Bush. That would pose a dilemma for Republican elders seeking to rebuild from the ruins of a potential landslide defeat.

“The liberal media are trying to skewer the vote so we won’t go out and vote,” said Flora Reece, 47, a commercial analyst. “We know he’s going to win. We know he’s going to be the next president of the United States.”

And if he doesn’t? Reece replied firmly: “There will be dead people who voted, non-registered people who voted. They bring immigrants here to vote for the Democratic party. The system is rigged.”

Trump’s followers, who include many newcomers to politics, are not prepared to fade quietly into the background, added Reece, who is African American and a member of her local Republican party. “People are too mad and too angry. They used to be lackadaisical but they got involved and found out that if you become part of a movement, you can change things.

The GOP establishment is bought and paid off. Right now you can’t tell the difference between Democrat and Republican Flora Reece

“The Republican establishment is bought and paid off. Right now you can’t tell the difference between Democrat and Republican. We’ve already planned to start a new party to bring independents, Democrats and Republicans together and take the White House back in four years.”

Melanie Parkham, 56, agreed: “Donald Trump has totally exposed how corrupt DC is. I’m sick of the Republicans too. I’ve heard a lot of people say they’re going to leave the Republican party.”

Asked what would happen if Trump lost, Parkham replied: “Hell, we’ll know Hillary Clinton had it rigged. I’ll switch to independent. I have friends in their 40s and 60s who have registered to vote for the first time in their lives so they can vote for Trump. I’ll make sure they stay interested.”

Trump’s post-convention tribulations just prompted Time magazine to publish a stylised image of his head dribbling like hot wax beside a single word headline: “Meltdown”. After his unwinnable fight with gold star family Khizr and Ghazala Khan, whose son died serving in Iraq, the candidate attempted to restore discipline last Monday with a major economic speech in Detroit.

Yet by Wednesday, he had touched off another furore with an off-the-cuff comment widely seen as inciting supporters of the second amendment to assassinate Clinton. A day later, he began repeatedly describing Barack Obama as “the founder” of Islamic State. He finally walked that back in the early hours of Friday morning.

As several polls showed the Democrat leading by double digits and beginning to threaten in red states such as Arizona, South Carolina and Utah – her campaign is even prodding Texas – more and more Republicans scrambled for the last lifeboats on the Titanic. Yet in Trump World, the prevailing narratives do not apply. Some supporters, for example, opined that Khizr Khan had been paid $375,000 to denounce Trump – an unproven claim perpetrated by rightwing websites – and was therefore fair game.

Capt Terry Shields, 66, a war veteran who served in Vietnam in 1969-70, said: “It was a shame it was brought up by the father in the first place. I think it was a fixed deal. The biggest thing that worries me is the Muslims taking over. It’s obvious that Obama is pushing them.”

Similarly, Trump’s comment about the second amendment was “all twisted” by the media, he added, a view echoed by many at the rally in Florida, a critical swing state.

Facebook Twitter Pinterest Trump supporters cheer before a campaign rally at the Silver Spurs arena in Kissimmee, Florida. Photograph: Eric Thayer/Reuters

Trump’s support base is, of course, no more a monolithic bloc than any other section of the electorate. Generalisations are perilous and pose a headache for post-election Republican strategists. Another military veteran, Brett Puffenbarger, 29, said: “I jumped on Trump train fairly early on. He was the only GOP candidate who wasn’t outright against gay marriage and legalisation of marijuana. He was socially liberal and fiscally conservative and that was a big draw for me.”

Sabrina Motes, 36, said: “I’m a Jewish American, I used to be a Democrat and I’m college educated. I hate the stereotype that if you’re college educated or Jewish you don’t support Trump. I’ve followed him in his business career and I believe he’s what the country needs right now.”

But looking to the future, Motes, a pharmaceutical sales rep, added: “I don’t think Trump is the perfect candidate. There are things that can be learned from and things that could be done differently. Republicans were supposed to learn from Mitt Romney but I don’t think they did.”

Allegations of rigging were widespread, even though a vote has not yet been cast, but few were willing to predict what kind of backlash there would be. Bob Kunst, 74, a registered but disaffected Democrat sitting behind a cardboard “Trump v Tramp” sign, said: “Right now the anger is intense and if, God forbid, Trump loses, you’re talking revolution. You’ve just had a revolution in Britain with Brexit.”

But Charlie van Esler, 60, an investment products seller who supported Marco Rubio in the primaries, said: “I have no reason to believe it would be a rigged election. I respect the democratic process. The idea that Trump supporters are rednecks and yahoos is disingenuous.”

Outside the arena, where Trump addressed thousands of (nearly all white) supporters, badges, hats, T-shirts and other merchandise were on sale. The Confederate flag was flying outside a stall run by Ariel Robb, a 26-year-old nurse, who insisted that its message “is more heritage than hate”.

He’s the only candidate who says if he makes a mess, he’ll clean it up. He’s a really intelligent man Ariel Robb

Trump claims that he has brought millions of new people to the Republican party; Robb is one of them. “He is the only candidate I’ve taken an interest in over the years,” she said. “He’s the only candidate who says if he makes a mess, he’ll clean it up. He’s a really intelligent man – and anything’s better than Hillary. I don’t think he’s going to lose and, if he does, I think Hillary will be impeached in the first week she gets in office.”

Meanwhile, Kelly Steele, 52, was shouting: “Get your ‘Make America Great Again’ hats and lapel pins, USA made!”, echoing the debate over US-based manufacturing versus global trade. “If he loses, I’m not looking to a man or woman to run this country. I’m trusting in God.”

Whereas Trump has a luxury home in Florida and beat local senator Rubio in the primaries, he fared less well in states such as Wisconsin. Earlier this week in Janesville, where post-industrial melancholy is evident in a closed car plant and eerily quiet downtown, House speaker Paul Ryan crushed a Trump-style challenger in a congressional primary. It was an important victory for the party’s establishment wing, which continues to battle far-right conservatives for Republican seats across the country, with mixed results.

Analysts dismiss the idea that, should Trump lose, a new wave of candidates will seek to emulate him in the 2018 congressional midterm elections. Heather Cox Richardson, an academic at Boston College and historian of the Republican party, said: “Donald Trump’s racist and xenophobic supporters are going to break off and do low-level violence. The Republican party is going to go into a far more progressive direction, back to the party of Nelson Rockefeller, Dwight Eisenhower and Teddy Roosevelt.

Facebook Twitter Pinterest Trump (and anti-Clinton) flair on a supporter’s hat. Photograph: Gregg Newton/AFP/Getty Images

“It’s a reinvention they’ve done before. The Trump supporters who are motivated by economic factors will gravitate back in a heartbeat. The idea that a party is going to win again by tying itself to voters over 65 is suicidal. Hanging on to this man is suicidal. What surprises me is how many people in the Republican party think their fortunes would be worse if they renounced him. I think people who haven’t, like Paul Ryan, are done.”

The Republicans could become the first party to lose the White House for three consecutive elections since the Democrats in 1988. A leading architect of the Democratic revival was Al From, who said on Thursday: “First the Republicans have got to develop an agenda that people want to vote for, not just a small sliver of the electorate.

“They’ve got to become more libertarian on cultural issues to appeal to young voters. You have to express views in ways that convey you’re open to other points of views, too. We weren’t going to win pro-life voters in 1992 but they saw Bill Clinton and said: ‘He’s not a radical on this, let’s look at what he says about other issues.’”

From warned: “If the governors and party leaders don’t take a stronger hand in shaping the party, it’s possible there will be some sort of replacement party. There could be a realignment of the parties over the next two or three elections. With the Republicans it’s more extreme because Trump has hijacked the party from the leadership. The leaders could take it back but it’s possible a third party could emerge.”

The GOP has been through these rough elections before, and they have emerged stronger and more unified quickly Frank Luntz

That argument echoes the recommendations of a Republican autopsy report, conducted after the 2012 election defeat, which called for wider appeal to young people and racial minorities and an end to the party’s anti-immigration stance. First the party could not bring itself to make that journey by passing a law in Congress – then Trump came along with his signature plan to build a wall.

Frank Luntz, a Republican consultant and pollster, also doubts that the maverick tycoon will have a long-term political legacy. He said: “Trump has little formal statewide organisation – even now. He has loyalists, but they are disorganised. His campaign is being out-raised and outspent by ratios we have never seen in modern politics – and that’s with just 90 days to go. There is absolutely nothing to suggest that this movement will continue beyond its leader. He has become the most unpopular political figure in America today.”

It would be foolish to write the Republican party off, Luntz added. “The GOP has been through these rough elections before, and they have emerged stronger and more unified much more quickly than prognosticators ever expected. The Goldwater debacle in 1964 led to Nixon’s resurgence in 1968 and a 60% landslide in 1972.

“Watergate may have destroyed the GOP in 1974, but Reagan won by nine [percentage points] just six years later and by 20 [points] four years after that. The loss of George Herbert Walker Bush in 1992 was supposed to be the end of the GOP, but they won the House and Senate for the first time in 40 years just two years later. Republicans are a very resilient party, and it doesn’t take long for them to recover.”