Image copyright Reuters

It is the final stretch of a brash, improbable campaign. Donald Trump is rolling through Florida's campaign stops; places like St Augustine, Tampa, Sanford, Tallahassee. It is a state he must win if he is to have a chance of claiming the White House.

His voice is a little weaker but he draws energy from large fired-up crowds who break into chants of "USA! USA!" In St Augustine, people were queuing from 10:00 for a 15:00 speech.

As the Trump team bounces from campaign stop to campaign stop, sweeping along cleared highways escorted by outriders, some advisers accept that crowd sizes don't necessarily translate into votes. And yet they wonder at the 12,000 (their figure) who turned out on Monday night in Tampa for a candidate some have written off.

Whether Trump goes down to defeat, he has built a formidable following. There can be a dangerous edge to the passion of his supporters.

Image copyright Reuters Image caption America first is a key theme of the Trump campaign

He speaks with the help of a prompter but he rarely sticks to his text. To his supporters his refusal to be scripted, to stick to the customs and niceties of political debate is a mark of his authenticity.

His core message remains; that a corrupt elite is running America for its own interests while the little guy is left behind, sacrificed on the altar of globalisation.

One Republican insider said that if Trump had just stuck to his economic pitch it might have been a different race but, to a degree, he has run against himself, his thin skin, his flaws and his sense of grievance.

Despite Trump's comments about women and the string of accusers who have come forward with allegations of sexual assault, they appear to have had little impact among his crowds, among his believers. He has - at least among his own supporters - defused a dangerous issue by promising to sue his accusers.

Instead, he focuses on what he calls the lies of "crooked Hillary Clinton". On Monday night, he declared "she lies more than any other human being". His crowds relish it, interspersing cries of "lock her up!" with boos at the mere mention of her name. If she wins, many in the country will doubt her legitimacy.

Image copyright AFP/GETTY Image caption Democrat nominee Hillary Clinton is a regular target of anger at Trump rallies

Trump's base, his core support, is holding up. His believers are impervious to revelations. They believe in a great conspiracy: that powerful corporations, wealthy donors and the media are taking the country from them. They may not understand this web of power but it rings true to them.

In St Augustine, Trump turned on the media depicting them as "these thieves and crooks… the media, they're almost as crooked as Hillary. Without the media she would be nothing... They're disgraceful." At that point a section of the crowd turns towards us on the media platform shaking fists of rage.

The undercurrent at the rallies is Americanism, of America first. The crowds are praised for their patriotism. You won't find chants of "USA! USA!' at Clinton rallies, they are told.

For a candidate behind in the polls one constant muse is Brexit. Trump often talks about it. It offers hope that somewhere out there among the rolling hills of the Republic there are hidden pools of voters, too shy to acknowledge they are Trumpeteers, much like the Leave campaign found during the referendum campaign in the UK.

Image copyright Reuters Image caption The media is another favourite target of Trump and his supporters

In the patient lines standing in the Florida sun waiting for access to the amphitheatres there is a willingness to talk.

Time and again I asked whether the election could be rigged as Donald Trump has suggested. Many believed it. Fewer said they would not accept the result if it went against them but some were ready to resist.

One man told me the situation was "scary". For months audiences have been told, "Don't let the establishment elites steal the election". There are many people pumped up, primed to contest an election that may go against them.

It is easy inside the bubble of the Trump campaign to forget the mountain he has to climb to secure the electoral college votes to win. His campaign has unleashed something powerful, something suppressed, something pent up: a deep longing for an America his supporters fear has been taken from them.

The maths of the electoral college suggest Hillary Clinton is going to win but Trump's crowds, undeterred by polls, makes one pause in a season of political upset.