President Joe Biden's campaign manager recently sent a fundraising email meant to reassure supporters worried about the Democrat's reelection chances, urging them to take a “quick walk down memory lane.”

Julie Chavez Rodriguez noted that many Democrats 12 years ago questioned whether President Barack Obama would win a second term. Biden was Obama's vice president.

“Flash forward to November 6, 2012. I think you may remember the day,” she wrote. Underneath was a photo of the Obamas and Bidens celebrating their election victory.

More than a nostalgic message, that sentiment can increasingly be seen in Biden’s strategy for winning in 2024.

Biden is trying to focus the campaign on former President Donald Trump's comments and policy proposals, sometimes more than his own. It's a time-worn strategy of White House incumbents to try to negatively define their rivals in the public's eyes. In 2012, Obama and his allies did it with Republican Mitt Romney, a former Massachusetts governor and current Utah senator. In 2004, President George W. Bush was successful against Democratic nominee John Kerry, then a Massachusetts senator.

But Trump, the current front-runner for the Republican nomination, is already better defined than perhaps any figure in U.S. politics. And even as Trump's promises to seek retribution and references to his enemies as “vermin” animate many Democrats, Biden faces low approval ratings and questions about his age and his handling of the economy and foreign affairs.

“You can’t really run a playbook for the last election, or what worked previously,” said Kevin Madden, a Republican strategist who was Romney’s 2012 senior adviser and spokesman. “I think Trump is an entirely different, nonlinear opponent compared to an Obama vs. Romney.”

Some prominent Democrats have suggested that there’s a danger in making the race too much about Trump. They say Biden should play up parts of his own record and focus on abortion rights after the Supreme Court overturned Roe v. Wade. Abortion was an issue credited with helping the party exceeding expectations in last year’s midterms and several races this year.

After spending much of his presidency declining to refer to Trump by name, Biden has stepped up his warnings about his predecessor. Biden's campaign has in recent weeks blasted Trump’s suggestions that he wouldn’t rule as a dictator “other than Day 1," that he would again pursue a repeal of Obama's health care overhaul, and that he would stage massive raids to try to deport millions of people.

Biden recently told a crowd of donors in Massachusetts, “We’ve got to get it done. Not because of me.”

“If Trump wasn’t running, I’m not sure I’d be running,” Biden said. “We cannot let him win.”

Trump's campaign did not respond to messages seeking comment. Biden’s campaign says defining clear contrasts between the president and Trump is key to its strategy.

“Next year’s election will be a choice between President Biden’s proven track record of lowering costs and delivering for middle class families, and Donald Trump and MAGA Republicans’ bleak vision of dividing us,” Biden campaign spokesman Ammar Moussa said, referring to Trump’s “Make America Great Again” movement. “We’re going to do the work to ensure voters understand the enormous stakes of next year’s election.”

Obama’s 2012 campaign relied heavily on grassroots organizing and television ad spending to motivate voters. Biden, though, is working to prioritize unconventional ways to reach voters in line with significant shifts in Americans’ media consumption habits, particularly about political issues.

The dynamics of the 2024 race are also different from 2012. Biden has a record of legislative accomplishments on popular issues such as infrastructure. In 2012, Americans were sharply divided over Obama’s signature accomplishment, the health care law often called “Obamacare,” though it is now viewed more positively.

Biden's aides also point to low unemployment and other signs of economic strength, although polls show Americans don't feel the economy is strong and they rate Biden poorly on the issue.

Obama campaign veterans hold key roles in Biden’s political operation, from White House senior adviser Anita Dunn, who worked in the Obama White House, to Chavez Rodriguez, a former Obama campaign volunteer and administration official.

Another, Kate Bedingfield, who was deputy campaign manager for Biden’s 2020 campaign and then White House communications director, said presidents always want to “make the campaign about their opponent and not their own record.” That is because governing means making compromises that can be sometimes harder to communicate in ways that resonate with voters, she said.

“They want to shift the dynamics of the race to be about the threat that their opponent poses,” Bedingfield said. “For the Biden campaign, in Donald Trump they have an almost existential threat.”

Obama built his winning campaign around attacking Romney months before Romney was formally the GOP nominee and defining him as a corporate raider willing to slash jobs to boost profits.

In 2004, Bush won reelection despite the growing unpopularity of the war in Iraq by portraying Kerry as a flip-flopper while pro-Bush groups ran a series of ads raising questions about Kerry’s record as a swift boat commander in Vietnam.

Biden has kept a relatively light schedule of campaign rallies, holding just one in the first four months after launching his reelection campaign. He has held dozens of private fundraisers and spent the past week raising money in Boston, Washington, and Los Angeles.

Obama didn’t hold his first reelection campaign rally until May 2012.

One of the most memorable pro-Obama ads featured an Indiana plant worker who described being asked to help build a stage from which the plant's employees were told they were being laid off. The plant worker blamed Romney and his private investment firm for making more than $100 million by shutting down the plant, a claim that the fact-checking site Politifact rated “mostly false.”

Efforts to vilify Romney only intensified when video emerged of him saying 47% of people would vote for Obama because they were “dependent upon government” and “believe that they are victims.”

Biden’s team has similarly picked up on economic themes to slam Trump, including promoting the story of electronics giant Foxconn. Trump promised as president that the company was building a major plant that would create thousands of jobs in the critical swing state of Wisconsin. Those jobs never materialized.

A year before the 2012 election, however, polls suggested Romney's public image could be shaped by negative ads in a way that Trump's cannot.

A Quinnipiac University poll conducted in late 2011 found voters were somewhat more likely to have a favorable than an unfavorable opinion of Romney, 36% to 31%. Notably, another 31% said they hadn’t heard enough about Romney to have an opinion.

A recent Quinnipiac poll found 42% of registered voters said they had a favorable opinion of Trump and 55% had an unfavorable opinion. The same poll found only 37% having a favorable opinion of Biden while 59% had a unfavorable opinion.

Bedingfield agreed that many voters have already made up their mind about Trump. But she said Biden was able to use Trump’s well-defined political brand against him in 2020 and could do the same next year.

“People looked at what he had done and said, ‘We don’t want more of this,’” she said of Trump. “That gives the Biden campaign a really strong roadmap.”

Stuart Stevens, who was Romney’s chief strategist, said that the country is now far more polarized than in 2012 and that the focus on Biden’s low polling numbers “is in the framework of a pre-Trump era.”

“I think we're really in a very different world,” Stevens said, adding that 2024 "is inevitably going to be more of a referendum on Trump.”