President Trump Donald John TrumpHR McMaster says president's policy to withdraw troops from Afghanistan is 'unwise' Cast of 'Parks and Rec' reunite for virtual town hall to address Wisconsin voters Biden says Trump should step down over coronavirus response MORE and his allies are laying the groundwork for a bruising and personal general election campaign strategy in the event Joe Biden Joe BidenCast of 'Parks and Rec' reunite for virtual town hall to address Wisconsin voters Biden says Trump should step down over coronavirus response Biden tells CNN town hall that he has benefited from white privilege MORE wins the Democratic presidential nomination.

Some in Trump’s orbit privately see a Biden candidacy as a potentially significant challenge to the president’s reelection chances, noting his strength with African American voters and public persona as a moderate with roots in Pennsylvania.

But publicly the president and some of his backers on the campaign trail and in Congress have already started deploying attacks on Biden’s son, Hunter, while painting the 77-year old former vice president as a bumbling candidate who lacks the mental fitness to run the country.

ADVERTISEMENT

The president has expressed surprise that Biden has vaulted himself into the front-runner position with a stellar showing on Super Tuesday.

“He looks like he's going to be a candidate and I just say, ‘How did that happen?’” Trump said Thursday during a Fox News town hall event in Pennsylvania.

Biden’s spot atop the Democratic ticket in November is far from assured with several primaries still to go. But he has been racking up endorsements as much of the party coalesces behind him, boosting Biden’s position to topple Sen. Bernie Sanders Bernie SandersMcConnell accuses Democrats of sowing division by 'downplaying progress' on election security The Hill's Campaign Report: Arizona shifts towards Biden | Biden prepares for drive-in town hall | New Biden ad targets Latino voters Why Democrats must confront extreme left wing incitement to violence MORE (I-Vt.), whose candidacy has sowed unease among the Democratic establishment.

The former vice president has long been seen as a top contender to defeat Trump, so much so that Trump ended up getting impeached and acquitted over a phone call where he urged a foreign government to investigate Biden.

Those close to the president and the campaign are lamenting the sudden shift in the Democratic race, where Sanders appeared to be the front-runner just a week ago. Trump and his associates believed Sanders, a self-identified democratic socialist, would present an easy contrast for the general election and could take certain swing states out of the mix.

One person close to Trump acknowledged Bernie has shown strength with a fervent base and impressive fundraising numbers, but argued his brand of politics would make it easy to paint him as a far-left socialist.

ADVERTISEMENT

“It’s a different race with Joe Biden,” the person said.

Biden has consistently led Trump in hypothetical head-to-head matchups in national polls. Biden and Sanders led Trump in recent swing state polls in Pennsylvania and Michigan, while both trailed the president in Wisconsin.

The former vice president has built strong support among black voters — a demographic the Trump campaign has made a point to court — thanks to his eight years as former President Obama’s second-in-command and decades of public service, despite his controversial vote on the 1994 crime bill and role in the 1991 Anita Hill Anita Faye HillAnita Hill says she'll vote for Biden Biden set to accept nomination in convention-closing address 50 years covering Biden MORE hearing.

Biden is also likely to pull in more moderates and some disaffected Republicans in the suburbs who may be hesitant to back Sanders’s more reformist agenda.

But Trump and his campaign have suggested they will have no problem painting Biden as a left-wing candidate should he secure the nomination.

Campaign officials believe the Democratic Party has pulled Biden to the left on issues like guns, and taxes to the point that his persona as a centrist is outdated. They pointed to his recent pledge have former Texas Rep. Beto O’Rourke lead the effort to rein in gun violence after O’Rourke said he’d support confiscating certain firearms.

The campaign against Biden would almost certainly also take a personal tone that targets the former vice president’s mental sharpness and his family.

Republicans in the Senate have already started moving forward with a probe into Burisma, a Ukrainian gas company that employed Hunter Biden on its board, in a sign it will be a major factor on the campaign trail.

The investigations represent a renewed effort to draw focus to corruption allegations that Trump and his allies leveled against the Bidens last year. There is no evidence of wrongdoing by either Joe or Hunter Biden in the matter and reporting has discredited the allegations, though government officials have acknowledged there was at minimum a conflict of interest.

"Any time this conspiracy theory is raised by the President or Senators who disrespect their office enough to transform their committees into craven arms of his re-election campaign, we will hammer -- with a baseball bat -- the fact that Donald Trump is hands down the most corrupt American president of all time," Andrew Bates, a spokesman for the Biden campaign, said in a statement. "If they really want to go there, they should buckle up."

The president said in a phone conversation with Sean Hannity Sean Patrick HannityTrump ABC town hall pulls in fewer viewers than 'America's Got Talent,' NBA, Fox News Dershowitz suing CNN for 0 million in defamation suit If Trump doesn't know why he should be president again, how can voters? MORE this week that he would bring up Burisma “all the time” to force Biden to address it.

“I firmly believe that Trump is going to make Hunter Biden the emails of the 2020 race,” said Democratic strategist Basil Smikle. “I also feel that Democrats are going to look at the president’s attacks and find them to be both hollow and hypocritical, but that doesn’t keep Republicans or voters who are the fence on their choice in 2020 from thinking twice about whether there is any veracity to the claims.”

ADVERTISEMENT

Some Republicans have been skeptical of the investigation’s appearance. Sen. Mitt Romney Willard (Mitt) Mitt RomneyGOP-led panel to hear from former official who said Burisma was not a factor in US policy Joe Biden's dangerous view of 'normalcy' The electoral reality that the media ignores MORE (R-Utah) — who supported Trump’s removal from office on the impeachment charge he abused his power by asking Ukraine to pursue an investigation into the Bidens last year — told reporters this week that it looked “political,” before ultimately agreeing to support a subpoena for a former consultant linked to Burisma Holdings.

“It’s so nakedly political that it’s almost comical,” said one former Republican National Committee official.

Multiple people close to the president and the campaign hypothesized that the best strategy to beat Biden may be as simple as giving the former vice president as much air time as possible and allowing him to speak unscripted.

Biden has long been viewed as gaffe prone, but in recent days he has shown why some Democrats are wary of him becoming the nominee.

Biden mistakenly told supporters last month he was running for “United States Senate.” He referred to Super Tuesday as “Super Thursday.” And in celebrating his victories on Tuesday, Biden mixed up his sister and his wife as they stood on stage beside him.

"Donald Trump thinks that windmills cause cancer, that climate change is a 'Chinese hoax,' calls himself a 'stable genius,' and has offered the groundbreaking insight that hurricanes are 'wet from the standpoint of water,' and told people it was fine to go to work when infected with coronavirus, which he's botching the federal response to right now," a Biden adviser said in response to the president criticizing the former vice president's mental fitness.

ADVERTISEMENT

The former vice president has been aggressive in his rebuttals to Trump. The president's personal attacks may even play into Biden's strategy, as he has often framed the 2020 election as a battle for the character of the nation.

Biden argued to NBC's "Today" that the president's attempts to get Ukraine to investigate him and his son were borne out of political fear. He and his allies repeatedly point to a lack of evidence to support any of Trump's Ukraine allegations.

Biden this week said Trump is running in fear, and linked Trump's impeachment trial to a lack of confidence he'll win a general election against the former vice president.

"He's even risked his presidency because he does not want to face me," Biden said.

Trump — whose own gaffes and behavior have raised questions among armchair doctors and Democrats about his fitness for office — has not been shy about raising questions about Biden’s mental aptitude, and he has done so in brash terms.

“You know, maybe he gets in because he's a little more moderate ... but he's not going to be running it,” Trump told supporters at a rally in North Carolina. “Other people are going to. They're going to put him into a home, and other people are going to be running the country and they're going to be super-left radical crazies.”

ADVERTISEMENT

Republicans see the focus on Biden’s gaffes as effective and some Democrats also acknowledge that such attacks are inevitable and that the party will need to find an effective way to defend against them.

“There are some Democrats who had doubts about Biden because of his gaffes and because of his debate performances whether they were tied to age or not,” said Smikle, the Democratic strategist.

“I do think you’ll hear that confidence come out that much more and you’ll hear a strength in his language and hopefully thereafter voters will forget about the early missteps,” Smikle added of Biden's recent appearances, which he said have shown the former vice president to be more confident following key primary wins.

Trump has made clear he has no qualms about engaging in personal and at times vicious campaigning, such as when he brought several women who have accused former President Clinton of sexual misconduct to a 2016 debate with Hillary Clinton Hillary Diane Rodham ClintonHillicon Valley: FBI chief says Russia is trying to interfere in election to undermine Biden | Treasury Dept. sanctions Iranian government-backed hackers The Hill's Campaign Report: Arizona shifts towards Biden | Biden prepares for drive-in town hall | New Biden ad targets Latino voters FBI chief says Russia is trying to interfere in election to undermine Biden MORE.

Trump on Thursday night laid out his mantra that when his critics hit him, “we have to hit back.”

“It’s just going to be a knockdown, drag out fight all the way through the year,” said former Trump campaign communications director Jason Miller. “And this is something President Trump is built for. I don’t think it’s something Joe Biden or Bernie Sanders are built for.”

Updated: March 8 at 7:00 a.m.