U.S. President Donald Trump formally launched his 2020 re-election campaign on Tuesday by presenting himself as the same political insurgent who shook up the Washington establishment four years ago and who is now a victim of an attempted ouster by Democrats.

At a packed rally at an arena in Orlando, Florida, Trump made clear he would run for re-election as an outsider, just as he did in 2016. Whether he can pull it off remains far from certain as Trump has been in office now for 2-1/2 years. 

He re-visited campaign themes from four years ago, decrying illegal immigration, the news media and his 2016 Democratic opponent, Hillary Clinton. 

"Together we stared down a broken political establishment and we restored government by and for the people," Trump said. "As long as you keep this team in place, we have a tremendous way to go. Our future has never looked brighter or sharper."

Trump said his Democratic challengers would radically change the United States and seek to legalize migrants coming across the southern border so they could vote and boost the Democratic political base. 

Democrats "want to destroy our country as we know it" and that it's "not going to happen," Trump said. 

"We believe our country should be a sanctuary for law-abiding citizens, not for criminal aliens," he said. 

Two dozen Democrats are competing for their party's nomination to face off against Trump in the November 2020 election. Many of the top Democrats lead Trump in opinion polls in battleground states.

Trump called his opponents a "radical left-wing mob" who would bring socialism to the United States. 

"A vote for any Democrat in 2020 is a vote for the rise of radical socialism and the destruction of the American dream," he said.

Airing grievances

Trump made his re-election launch official at what was his 60th political rally since he took office in January 2017. He brought his wife, Melania, and a large contingent of senior White House staff. 

"Tonight I stand before you to officially launch my campaign for a second term as president of the United States," Trump said. "I promise you I will never ever let you down."

He made an issue of Special Counsel Robert Mueller's investigation into Russian interference in the 2016 election. The probe found insufficient evidence to establish that the Trump campaign engaged in a criminal conspiracy with Moscow. It also described numerous attempts by Trump to impede Mueller’s probe, but stopped short of declaring that he committed a crime. 

"We went through the biggest witch hunt in political history," said Trump. "It was all an illegal attempt to overturn the results of the election." 

Mueller report shows no evidence that Trump campaign conspired with Russian gov't

"If the economy stays strong, he is very likely to get re-elected," said Trump confidant Newt Gingrich, a former Republican speaker of the U.S. House of Representatives.

Democrats cite a string of broken promises in Trump's first term, from lowering drug prices to closing corporate tax loopholes and stopping plant closures.

"Donald Trump is launching his campaign for re-election tonight 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," said Kate Bedingfield, deputy campaign manager for Democratic front-runner Joe Biden.