DONALD TRUMP PUSHED into arguably the most important state on the electoral map yesterday, opting for a rally in Pennsylvania instead of formal debate practice two days ahead of the final presidential debate that may be his last and best chance to alter the trajectory of the 2020 campaign.

Democrat Joe Biden took the opposite approach, holing up for debate prep in the lead-up to Thursday’s face-off in Nashville.

But Trump, trailing in polls in most battleground states, continued his travel blitz in the race’s final fortnight and delivered what his campaign has wanted to be his closing message.

“This is an election between a Trump super recovery and a Biden depression. You will have a depression the likes of which you have never seen,” the president said in Erie, Pennsylvania.

“If you want depression, doom and despair, vote for Sleepy Joe. And boredom.”

But the president’s pitch that he should lead the rebuilding of an economy ravaged by the pandemic has been overshadowed by a series of fights.

In the last two days he has attacked the nation’s leading infectious disease expert and a venerable TV news-magazine while suggesting that the nation was tired of talking about a virus that has killed more than 220,000 Americans.

Before leaving the White House, Trump taped part of an interview with CBS programme 60 Minutes that apparently ended acrimoniously.

On Twitter, the president declared his interview with Lesley Stahl to be “FAKE and BIASED,” and he threatened to release a White House edit of it before its Sunday airtime.

Also trailing in fundraising for campaign ads, Trump is increasingly relying on his signature campaign rallies to deliver a closing message to voters and maximise turnout among his GOP base. His trip yesterday to Pennsylvania was one of what is expected to be several to the state in the next two weeks.

“If we win Pennsylvania, we win the whole thing,” Trump said in Erie.

Erie County, which includes the aging industrial city in the state’s north-west corner, went for Barack Obama by 5 percentage points in 2012 but broke for Trump by 2 in 2016.

That swing, fueled by Trump’s success with white, working-class, non-college-educated voters, was replicated in small cities, towns and rural areas and helped him overcome Hillary Clinton’s victories in the state’s big cities.

But the president will likely need to run up the score by more this time around as his prospects have slipped since 2016 in vote-rich suburban Philadelphia, where he under-performed by past Republican measures.

This raises the stakes for his campaign’s more aggressive outreach to new rural and small-town voters across the industrial north.

His aides worry that his opponent is uniquely situated to prevent that, as Mr Biden not only hails from Scranton but has built his political persona as a representative of the middle and working classes.

Meanwhile, Obama is returning to Philadelphia for his first in-person 2020 campaign event for his former vice president. He will speak on Wednesday at a drive-in rally, where supporters will listen to him over the radio inside their cars.