Republican nominee Donald Trump and Democratic nominee Hillary Clinton before their first presidential debate at Hofstra University in Hempstead, N.Y., in September 2016. Evan Vucci/Associated Press

WASHINGTON — Gearing up to take on Democratic front-runner Joe Biden, President Trump sees echoes of his 2016 foe, Hillary Clinton.

Despite polls that show Trump trailing the former vice president in battleground states, the Republican president is relishing the chance to wage against Biden what he believes will be a redux of his successful 2016 campaign. Central to the strategy for Trump, 73, is to try to paint the 76-year-old Biden as old and doddering, while hammering away at vulnerabilities in Biden’s past – the same cudgel Trump used against Clinton.

“Joe Biden, he looks like he’s just exhausted,” Trump told Telemundo on Thursday. “I don’t know what happened to him, but he is exhausted and he doesn’t do any work. He’s not working.”

The rhetoric shows how Trump is trying to recalibrate his attacks on potential rivals as the crowded Democratic primary unfolds.

In the earliest days of the contest, he sought to seize on Bernie Sanders’ liberal ideology to paint all Democrats as socialists, an effort that became more complicated when Biden rose to the top of the pack. Trump still rails against the threat of socialism, but if Biden comes out on top, the president is ready to embrace his tried and true 2016 playbook: exploiting his rival’s record in public life and sowing doubts about his fitness for office.

Former Vice President Joe Biden campaigns last week in Clinton, Iowa. Biden has sat atop the crowded Democratic presidential field from virtually the moment he joined the race. Charlie Neibergall/Associated Press

The approach fits into Trump’s broader obsession with his 2016 victory, which he recalled again to great fanfare this week as he launched his re-election bid from an Orlando stadium. Advisers insist applying the standards of 2016 to Biden is about more than bravado.

“The fundamental contrast between them means it’s a very similar playbook to run in 2020,” said Jason Miller, Trump’s 2016 senior communications adviser. “Everything Biden says can come back to a half century in office and a half century of promises.”

Trump faces several risks in trying to turn next year’s election into a carbon copy of 2016. His own aides have repeatedly cautioned in White House meetings against elevating Biden from the pack of nearly two-dozen Democrats running.

And it’s possible that Clinton’s vulnerabilities were unique to her. While she and Biden have both been in the public eye for decades, Clinton was a lightning rod in the nation’s culture wars in a way Biden never has been.

Still, Trump isn’t likely to be deterred. He plans to hit Biden on the Obama-era policies that animate the GOP base, such as the Iran nuclear deal, along with Biden’s support for the 1994 crime bill and 2002 Iraq War vote, which are out of step with the ascendant progressive wing of the Democratic party.

Nearly three years after the last campaign, Trump still fans the flames over Clinton’s use of a private email server as secretary of state. “They never look at Hillary Clinton’s e-mail deletions,” Trump said in an interview last week with “Fox & Friends.”

Now Trump and his allies have tried to gin up a similar scent of scandal around the former vice president, with the president’s personal attorney Rudy Giuliani and other advisers spreading largely unsubstantiated allegations of conflict of interest. They claim that as vice president, Biden pushed the Ukrainian government to fire a prosecutor viewed as an obstacle to good-governance reforms, while his son, Hunter, was on the payroll of a Ukrainian energy firm.

In an interview with The Associated Press in May, Biden denied Hunter Biden’s work for the company had anything to do with the effort.

“We never once discussed it when he was there,” Biden said of his son.

While Trump will undoubtedly try to find vulnerabilities to exploit in any opponent, Democrats are sounding alarm at the similarities to his first campaign.

Brian Fallon, Clinton’s 2016 press secretary, said Biden was “susceptible” to the same sort of attacks Trump deployed on Clinton. “I don’t think those attacks were fair but they may well have had an effect,” he said.

Trump’s campaign used Facebook and other tools to dampen enthusiasm of younger voters and voters of color and sow doubts about her health and private email usage. Combined, Clinton’s team believed the attacks weakened their coalition and cost her the White House – a key reason they’ve been outspoken in calling for social media companies to do more to fight disinformation and suppression.

Fallon said it was imperative for Biden or any Democratic nominee to define their campaign not just as a reaction to Trump – which he said could lead to “death by a thousand cuts” in endless scuffles with the president – but to pick fights of their own to boost Democratic enthusiasm and win over swing voters.

Other Democrats doubt that voters will give Trump’s familiar tactics a pass.

“Donald Trump wants to run for president in the same way he did last time and the same way he ran his businesses – by promoting conspiracy theories and tabloid smears,” said Jesse Ferguson, a Democratic strategist and former Clinton spokesman. “That’s all he knows how to do, but the American people are onto his scam.”

The focus on Biden, Trump allies stress, reflects his standing in Democratic polls, and they have yet to invest significant resources into preparing to run against any candidate. Should another candidate emerge as the nominee, Trump’s team believes the “socialist” frame will stick.

Trump’s campaign insists preparations to run against any specific 2020 Democrat is premature, given the chaotic nature of the Democratic field.

“If there is a similarity between Hillary Clinton and Joe Biden it’s that they’re both swamp creatures from DC,” said Trump campaign communications director Tim Murtaugh.

Democrats counter that Trump has his own vulnerabilities, including his recent assertion that he’d be open to accepting a foreign power’s help in his 2020 campaign.

“An American President should not seek their aid and abet those who seek to undermine democracy,” Biden tweeted.