Donald Trump attacks Joe Biden at Minneapolis rally as campaign targets Minnesota

Donald Trump told his supporters that the Democrats were trying to "erase" the result of the 2016 election as he launched a fiery counter attack on Joe Biden in his first rally since the impeachment proceedings began.

"They want to erase your vote like it never existed," he told a crowd in Minneapolis.

"They want to erase your voice and they want to erase your future."

Thursday night's rally was the US president's first chance to test out a new line of attack against the Democratic impeachment probe, issuing scathing personal insults against Mr Biden and other leading Democrats.

Of Mr Biden, who is likely to be his main political rival in 2020, Mr Trump said: "[He] was never considered smart, he was never considered a good senator. He was only a good vice president because he knew how to kiss Barack Obama's a--."

At another point, he repeated his claims that Mr Biden used the vice presidency for his own and his son Hunter's financial gain, saying: "The Bidens got rich, and that is substantiated, while America got robbed". The Bidens have always denied the allegations.

Mr Trump even floated the idea of producing campaign T-shirts about Hunter Biden - who he slammed as "a loser" who knows "nothing about anything".

Mr Trump also turned his fire on Nancy Pelosi, the Democratic House Speaker, saying "she's either really stupid or she's really lost it" to loud jeers from the crowd.

The US president is hoping to use the impeachment investigation as a mechanism to energise his support base, telling the audience the Democrats' decision would "produce a backlash at the ballot box, the likes of which they have never ever seen before in the history of this country."

Mr Trump has painted himself as a victim of a "witch hunt", the refrain he used throughout the Russia investigation, and is using the threat of impeachment as a rallying cry for his supporters, holding two more re-election rallies across the country within the next week.

Mr Trump was joined by his vice president, Mike Pence, who told the crowd that Democrats have spent the last three years trying to "overturn" the 2016 result.

"Now, Minnesota, it's our time to fight for him," he said.

Mr Trump's re-election strategy is largely focused on energising his 2016 voters to turn out next November, particularly in the Rust Belt.

Minnesota, a state Mr Trump lost narrowly to Hillary Clinton in 2016, is a key target for his re-election campaign in 2020. Mr Trump has been building a network of campaign staff and volunteers since June, hoping to become the first Republican president to win Minnesota since Richard Nixon carried the state in 1972.

The state is also home to Ilhan Omar, one of four liberal congresswomen known as the "squad," who Mr Trump has framed as the "radical left" who have seized control of the Democratic party.

"Congresswoman Omar is an America-hating socialist," Mr Trump said on Thursday night.

"She is one of the biggest reasons that I am going to win and the Republican party is going to win Minnesota in 13 months."

As he stepped on stage, Mr Trump said his campaign had set a new record, with 20,000 people filling the city's Target Centre basketball arena.

But outside the arena, the city's political divides were on display. Opposing groups of protesters began gathering ahead of the rally to express their view of the president. A number of businesses were closed all day, keen to avoid trouble with thousands of anti-Trump protesters forecast to throng the streets around the arena.

Unperturbed by the rain, many blew on brightly coloured whistles, others carried along drums to create a din that could even be heard within the arena's press section. The raucous noise was accompanied with chants of, "Lock him up! Lock him up! Lock him up!" - referring to Mr Trump.

As the protests grew more raucous, with Trump supporters reportedly attacked and merchandise set alight, hundreds of riot police were dispatched to surround the area.

Billie Isaac, a cafe worker from Minneapolis, said she had experienced the impact of the political division first-hand. Ms Isaac began queueing for Mr Trump's rally at 3am, hoping to get a front-seat view of the president. But she was not accompanied by her husband, who is not a great fan of Mr Trump or his immigration policies.

"You can't even talk to the opposite side because it gets into an argument," she said.

"It's not a good feeling, I had a lot of friends that I don't have anymore because I support Trump. They just don't understand how I can, and I don't understand how they can't."

But she believes the ongoing impeachment investigation is going to backfire on the Democrats, "just like the Mueller report did".

Inside the arena, Jesse Wood, a 40-year-old landscape contractor, said he thought Mr Trump's phone call with the Ukrainian leader was a "bad thing" but added: "should he stop being president because of it? I don't understand it."

He added that he did not believe the Democrats "feel strongly about it, but they're trying to do whatever they can to sabotage him".