Swimming in nostalgia, Trump played all the old hits . He bashed Hillary Clinton, jabbed the "fake news," invoked fear over immigrants and marveled at the glory over his shock election win.

He partied like it was 2016.

Holding forth from the pounding heart of a rapturous crowd, the President spelled out a defiant, demagogic, fact-blurring record of promises kept that could win him reelection.

But Trump's ceremonial 2020 campaign launch rally also reverberated with the unity-shredding grievances that threaten to whip up equal fervor against him and could make him a one-term President.

The rally, in a cacophonous Florida arena, and the first Democratic debates next week will lift the nascent 2020 campaign to a new level of intensity that will clarify a fateful choice that voters must make about the most disruptive, unconventional President in American history.

For a few moments Tuesday, it sounded like Trump might ditch his trash-talking after channeling Ronald Reagan's classic "Morning in America" reelection mantra -- are you better off now than you were four years ago?

"Our country is more thriving, prospering and booming and truly it is soaring to new heights," Trump said, claiming stewardship of "perhaps the greatest economy" in US history and millions of new jobs, roaring manufacturing and rising wages.

He was coining the best argument he has to make for staying in his job.

But soaring rhetoric fast dissolved into searing attacks, signaling that Trump believes that the scorched-earth campaign that won him the White House will send him back there.

"We did it once, now we will do it again and this time we are going to finish the job," Trump vowed, gripping the presidential podium with his left hand, and conducting his sing-song delivery with his right hand waving in the air.

Trump torched the media, conjured cataclysmic imagery of "criminal" immigrants, issued harangues against elite insiders rigging the system and slammed "ruinous trade" deals.

He vowed to find Clinton's emails, accused Democrats of "destroying the country." He claimed he "won" with special counsel Robert Mueller's Russia report and falsely said Democrats are "ripping" babies from their mothers' wombs.

His assaults were typical of the base-pleasing strategy from which Trump has never diverted during a turbulent two-and-a-half years in office and makes the root of his appeal.

Earlier, there was a taste of the character assassination to come when Trump's son, Donald Trump Jr. warmed up the crowd by accusing Democratic frontrunner Joe Biden of "groping" and mocked the cancer moonshot of a man whose son died of the disease.

Prosperity and security

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But the President leavened the bile with a more conventional approach, seeking to draw in wavering mainstream Republicans and independents left uncomfortable by his populist, nationalist creed. He built an argument rooted in prosperity and security, noting his scores of judicial appointments, two new Supreme Court justices and attempts to fight opioid addiction

He feted his shift of the US embassy in Israel to Jerusalem , lauded his withdrawal from the "disastrous" Iran deal, despite boiling tensions some fear could erupt into war with Tehran.

Hitting a political note that will resonate in swing state Florida, Trump vowed to fight for freedom in Cuba and Venezuela, and said America must always put its own people first.

He also celebrated his support of the Second Amendment, promised to back research to cross new medical frontiers, to cure HIV/AIDS and to put American astronauts on Mars.

Often, a President starting the march to reelection looks rusty after months waging Washington duels and West Wing crises, like a rock star who takes a while to hit his highest notes.

Not Trump.

After all, he never left the road to come up with new material and has ground out 50 campaign trail rallies since taking office and runs a permanent campaign on Twitter.

His appearance was a reminder of the unique and often dark political skills that Trump brings to the race. No one on either side can play a crowd like Trump. No Democrat has come near the size of his throng on Tuesday night. And his fervent, loyal flock looks like it is as up for the fight as it was in 2016.

Between applause lines lapped up by the giant crowd, Trump prowled the stage, arms hanging at his sides, like a heavyweight boxer gathering for another punishing combination of punches.

Trump's gamble

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But Trump's approach is a a huge risk.

It mirrored his strategy in the 2018 midterm elections that many Republicans blame for scaring suburban women and independent voters and handing Democrats the House.

The President did little Tuesday to answer the questions that Democrats believe will define the election, namely the struggle many Americans have in affording health care, the massive student loan burden and tax cuts they say soaked the rich.

The President only mentioned his most well placed opponent, Biden, in passing on Tuesday night, calling him "sleepy."

But the former vice president's team made their own attempt to define the race, issuing a statement before Trump took to the stage, rooted in his quest to restore America's soul.

"Donald Trump is launching his campaign for reelection and the American people face a choice -- we can make Trump an aberration or let him fundamentally and forever alter the character of this nation," deputy campaign manager Katie Bedingfield said.

Tuesday night's rally could include the seeds of Trump's victory. But he is betting America, having seen what life under the most disruptive President in modern history is like, will welcome a rerun of his polarizing campaign.

Polls more than 500 days before election day are not predictive of the final result. But currently they suggest trouble looming. In most surveys Trump trails Biden by a significant margin, and is also behind other major Democratic candidates.

New Quinnipiac University numbers reveal a potential flaw in Trump's big argument that Americans would be foolish to hand Democrats the White House amid a historic economic expansion.

Fifty-four percent of Florida voters said they are better off financially today than in 2016. But Biden leads Trump 50% to 41% despite those views. Fifty-five percent of independents and 45% of women say they are in better financial shape under the Trump economy. But those groups back Biden by 54% and 58% respectively.

Given Florida's recent presidential election history, it seems unlikely that either candidate will win the crucial state by nine points come November 2020.

But Tuesday night was a sign Trump knows he's in for a fight of his life in a battleground that could decide his fate. And it also shows there's been no erosion in his immense campaign trail skills it will take to win it.