Lexington (United States) (AFP) - Taking the stage in a packed Kentucky arena to the strains of America's unofficial patriotic anthem, "God Bless the USA," Donald Trump didn't look like a man in trouble.

Harried by impeachment proceedings, yes. Beset by foreign policy worries, yes. Accused of everything from sexual assault to incompetent White House management, yes.

But Trump resembled a man younger than his 73 years and considerably happier than a president likely to become only the third in history tarnished by impeachment.

The ear splitting cheers from the crowd of around 20,000 in Lexington's Rupp Arena explained why.

Dressed in red "make America great again" baseball caps and carrying "Trump 2020" placards, this hardest of the hardcore Trump base was delirious even before the president took the stage.

They'd warmed up to 1980s golden oldies, but Michael Jackson and company could not compare to the excitement triggered by Trump's entry.

And Trump had his own greatest hits.

Within a few minutes, he'd boasted that US special forces sent Islamic State's late leader Abu Bakr al-Baghdadi "to hell," that the Democratic party is "crazy," and joked that he might ignore constitutional term limits to stay in power for the rest of his life.

Classic Trump.

Even when it came to the ostensible reason for his speech in Lexington -- to rally voters around Republican incumbent Governor Matt Bevin in an election Tuesday -- Trump was classic unconventional Trump.

"He's a pain in the ass," Trump said of the governor he was supporting.

The crowd cheered: this was the performance they'd come for.

- Solid base -

By many measures, Trump's presidency is wobbling. His national approval ratings are in the low 40 percent range and Democrats are lining up to throw him out of office in 2020.

Allegations that he used US aid to Ukraine to try and pressure the government into opening an embarrassing investigation of Democratic opponents will likely see Trump impeached in coming months. Even if Republicans protect him in the Senate and he stays in the White House, as seems assured, Trump is seemingly in perilous territory.

Story continues

But in front of his rightwing base, a different picture emerges.

Trump tapped into popular anger against the establishment in 2016 and three years into his first term he believes the same formula will work again.

Seen through that lens, impeachment isn't damaging -- it's an elixir, a boost that "has created an angry majority that will vote the do nothing Democrats the hell out of office," he said.

He may have a point: a New York Times/Siena poll published Monday found that while Trump has flimsy support across the nation, his base remains solid in key swing states where elections are actually won.

Crucial to that base were white, working-class Americans in places like Pennsylvania and Wisconsin. And according to the poll, those voters are still there for Trump.

The same demographic turned out at the basketball arena in Lexington on Monday night and Trump clearly knew which buttons to hit.

Protection for gun ownership, restriction on abortion, military spending -- he gave them what they wanted.

"You have a president who is standing up for America," he said. "The great betrayal is over."