WASHINGTON (AP) — President Donald Trump and his allies are planning sustained personal and reputational attacks against Joe Biden, casting him as ill-equipped for the presidency and pushing unsubstantiated claims of corruption as he emerges as the favorite for the Democratic nomination.

The president and his top campaign aides are stoking division among Democrats, arguing that Biden is only taking the lead in the Democratic contest because the party's establishment is aligned against progressive rival Bernie Sanders. Fox News host Sean Hannity is portraying the 77-year-old Biden as a doddering old man, devoting nearly 10 minutes of his show Tuesday night to what he called “disturbing" verbal miscues.

And some Republicans in the Senate are moving to ensure there will be renewed scrutiny of Biden's son Hunter and his ties to a Ukrainian gas company that put him on its board while his father was vice president. There's no evidence that Biden or his son engaged in misconduct with Burisma, the gas company.

The sometimes-misleading tactics are a reprise of Trump's 2016 playbook against his Republican foes and, ultimately, Hillary Clinton. By deploying the same methods, Trump and his allies believe that voters will favor the president's combative nature and emphasis on conflict over Biden's appeal to restore decency and honesty to the White House.

But that burn-it-down style will be tested anew before a Democratic Party that is showing signs of greater unity against Trump than four years ago and hopes to build on victories from the 2018 midterms.

“Increased turnout and all of these big wins across the country make clear voters aren't buying what Trump is selling this time," said Scott Mulhauser, a Democratic strategist and former Biden spokesman. “They know the Vice President, they like him and it's clear they think he can win in November.”

But some Republicans warn against overconfidence by Democrats and note that Trump has a unique ability to define his opponents in ways that resonate.

“We’ve seen this movie before. Nobody is better at driving a narrative about his opponents than Donald Trump,” said Republican consultant Terry Sullivan, who ran Marco Rubio’s 2016 presidential campaign. “Love him or hate him, there is no denying that he is a branding master.”

Biden has been the most-targeted Democrat of the cycle by Trump's campaign. The president spent more money attacking Biden on Facebook than all the other Democratic candidates combined, according to the Bully Pulpit campaign tracker. That was true even before Super Tuesday, when Biden shocked his rivals with sweeping victories across the country.

Trump's focus on Biden reflects concerns from the president and his team that the former vice president could be a tough opponent, particularly among working-class voters who left the Democratic Party in 2016. Biden has argued he can reclaim states like Michigan, Pennsylvania and Wisconsin, which were crucial to Trump's victory in 2016.

That argument was bolstered on Tuesday when Biden scored a commanding win in the Michigan primary, attracting support from both African Americans and working-class whites.

Trump was so fixated on Biden last year that he asked Ukrainian leaders to investigate him, a move that prompted the president's impeachment by the Democratic-led House. He was acquitted by the Republican-led Senate.

At points when Biden seemed to fade, Trump shifted to Sanders, who had strong showings in the first contests of the Democratic primary and was briefly the front-runner. Trump repeatedly blasted Sanders and told audiences at his rallies that the U.S. would never be a socialist country, a reference to the Vermont senator's embrace of democratic socialism.

But after Biden's campaign rebounded late last month in South Carolina and posted resounding wins in many of the March contests, he's again the subject of the president's attention.

Trump has turned a recitation of Biden gaffes into a running gag line at his political events and fundraisers.

“There’s something going on there,” Trump, 73, told Fox News in a town hall last week.

Biden’s verbal stumbles have been a focus of Republicans as they seek to rebrand the famously off-the-cuff former vice president, who made Dairy Queen stops between official events while serving in the White House, as more of a “career politician” than his everyman reputation would suggest. They note his record in Washington is even longer than Clinton’s was, and that on substantive issues, like trade, Biden supported deals like the North American Free Trade Agreement and the Trans-Pacific Partnership.

For the last month, Trump’s campaign has been sowing intrigue over the Democratic Party’s swift coalescing around Biden at the expense of Sanders, trying to reignite anger over the Vermont senator's treatment by the Democratic Party in 2016.

In a statement late Tuesday, Trump campaign manager Brad Parscale said it was “clear that the Democrat establishment has rallied around the confused Joe Biden in an effort to deny the nomination to Bernie Sanders.” Trump has echoed the notion in tweets, claiming without evidence that Massachusetts Sen. Elizabeth Warren, “working in conjunction” with the party, sunk Sanders' campaign when she waited until after Super Tuesday to get out of the race.

Trump’s campaign acknowledges that there are “loud echoes” of the anti-Clinton effort as the 2020 focus zeroes in on Biden. It plans a multifaceted effort to drive up Biden’s negative ratings by exploiting the Sanders discontent and by stoking questions about Biden’s fitness for the job and his son’s business record.

Biden and his aides have looked to past campaigns for reminders of the danger of being defined early by opponents. Clinton never outran the attention to her use of a private email server as secretary of state and questions about the activities of the Clinton Foundation.

John Kerry's 2004 presidential campaign similarly fell short when a group of Vietnam veterans questioned his war valor, despite military records backing up his litany of medals.

In both cases, the Democratic nominees did not immediately react to the onslaught, eventually drawing critiques even from supporters that they let their attackers sway public opinion too much. Biden's inner circle plans to take a different, more aggressive course.

Immediately following the release of a White House whistleblower’s report that became the foundation of the House impeachment case against Trump, Biden himself went on the offensive.

“Vladimir Putin doesn’t want me to be president … and Donald Trump doesn’t want me to be the Democratic nominee because he knows I’ll beat him like a drum,” Biden began telling his campaign audiences.

Biden often notes that he's released decades of his tax returns and tauntingly dares Trump to do the same. Biden called an Iowa voter who questioned his defense of his son “a damn liar,” and he’s repeatedly admonished reporters to “ask the right questions.”

His aides have similarly pressed the media not to simply fact check Trump, but to also actively debunk falsehoods from the president and his allies.

Biden's campaign believes their biggest advantage over Trump's attacks is the former vice president's likability. As he's consolidated support from Democratic lawmakers and other power brokers, his backers often say they're endorsing Biden because “we know Joe.”

“He’s been known for decades as someone who is true to himself and speaks his mind," said Andrew Bates, who runs Biden’s rapid response operation. "This is not some over-calculating politician.”

“On balance,” Bates said, "that becomes an enormous strength.”

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Barrow reported from Atlanta.

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