For Donald Trump, patriotism is chief among virtues, yet his love of country is tempered by an apocalyptic vision of a nation plundered by criminal migrants, beset by rampant inflation and brought low by the forces of liberalism.

"We are a nation in decline," he declares with metronomic regularity as he vies to lead a country experiencing plunging crime and an economic boom, having led the world in the recovery from the pandemic.

Trump's version of America is under siege from an "invasion" across its southern border. Girls are "raped and sodomized and murdered" by foreign hordes "poisoning the blood" of the nation. People's pets are on the menu at migrant barbecues.

If he falls short in his bid for a White House return, so the impressively consistent messaging goes, the last person out of the United States should remember to turn out the lights.

"Our country will sink into an economic depression," Trump warned during a recent exchange with voters. "Your electric bill is going to go through the roof."

The 78-year-old has always been given to wild hyperbole and his rhetoric on immigration verged on apocalyptic during his victorious 2016 campaign, and again during his defeat in 2020.

But his tone has become bleaker, notes political scientist Julian Zelizer.

Marxist, communist... fascist?

The Princeton University historian told AFP that Trump watchers in 2024 have been hearing "similar messages" as in previous campaigns -- but "all of this on steroids, and with even fewer guardrails."

The recalibration has been intensified since Vice President Kamala Harris unexpectedly replaced President Joe Biden as the Democratic candidate this summer.

Without any foundation, Trump has insisted that his new rival wants to "execute babies" with her pro-abortion rights agenda, is a Marxist, a communist and -- simultaneously -- a fascist who is "mentally impaired."

Along with the foreboding, racially divisive rhetoric, Trump has long had a reputation for being cavalier with the truth.

One recent example came as he visited hurricane-hit Georgia, and related an entirely fact-free story about Biden failing to make himself available to local authorities in charge of the rescue and recovery effort.

"We've all become desensitized," Nobel Prize-winning economist Paul Krugman noted on X.

"But it's amazing how at this point the Trump campaign rests entirely on denouncing things that aren't happening -- imaginary bad economy, imaginary runaway crime and now an imaginary failure of Biden and Harris to respond to natural disaster."

Trump has seldom suffered consequences for his false claims, with his party crowning him as their election nominee for a third time in July, days after an attempt on his life at a Pennsylvania rally.

His base revels in quasi-messianic tales of their hero being saved from the gunman's bullets by the hand of God.

In addition to their signature red "Make America Great Again" caps, his supporters have taken to sporting T-shirts depicting Trump with fist raised and ear bloodied in the attack.

"If somebody was to shoot at Trump, I'd be the first to jump up and try to get in the line of fire to save his life, because his life in more important than mine," 71-year-old Donald Owen told AFP at a rally in Flint, Michigan.

'When I go bad'

When his speeches are not drawing criticism for their sinister tone, they are occasions for opponents' mockery.

Democrats share Trump's clips on social media, laughing at his flights of fancy about non-existent man-of-the-year awards and helicopter emergencies, and his oddball thought-experiments about shark attacks and maritime electrocutions.

The Republican has been clear that this White House campaign will be his last, although he brushes off questions about his age and mental fortitude.

"I'll let you know when I go bad. I really think I'll be able to tell you," he once told his supporters.

For his critics, that ship has already sailed, but many fear he will not go quietly if he is rejected by voters for a second election running.

Trump was impeached for inciting an insurrection to halt the peaceful transfer of power to Joe Biden in 2021.

He still has not acknowledged that he lost and faces multiple felony charges over alleged attempts to overturn the result.