Joe Biden is facing a tough reelection battle. These are the 4 obstacles for his 2024 campaign.

WASHINGTON — Any way you slice it, President Joe Biden faces a tough reelection battle in 2024.

The incumbent president trails former President Donald Trump and other Republican White House hopefuls in pre-election polls, his numbers driven down over voters' concerns about his age and the economy. Though Biden's Democratic challengers, author Marianne Williamson and Rep. Dean Phillips, D-Minn., haven't gained much traction with voters, Biden still hears calls for new leadership within his own party.

"I guarantee I’ll work like the devil," a confident Biden told backers at a fundraiser last month in Bethesda, Maryland. "And I guarantee you: We make our case, we win."

As the first-term president proceeds to make his case in 2024, he and his campaign face at least four major challenges. Here's what you need to know.

Dealing with age

Biden, who turned 81 in November, is already the oldest president in American history and would turn 86 at the end of a second term.

Polls show voters have qualms about the incumbent's age as he seeks another term in office. A Monmouth University poll in October found that 76% of voters "agree that Biden is too old to effectively serve another term as president." A USA TODAY/Suffolk University poll last year found that 37% of Democratic and Independent voters say the president's age makes them less likely to vote for him.

But a 56% majority said it did not make a difference to them, and Biden's supporters say his age is an asset.

"His success as president is because of his age and his experience and his wisdom," said Democratic strategist Simon Rosenberg.

Some Democrats also note that Trump turns 78 years old in June and has had his share of mix-ups on the campaign trail, such as accusing Biden of trying to start "World War II."

While Trump has mocked Biden's occasionally slow movements, he admitted in an interview with NBC's "Meet the Press" last year that he doesn't think Biden is too old to be president.

A fraying coalition

The Biden campaign must also rebuild the Democratic coalition that propelled him into office in the 2020 election. A new USA TODAY/Suffolk University Poll shows the incumbent with lower-than-usual support among young people, Hispanic voters and Black voters.

Biden currently claims support from only 63% of Black voters, the poll said, down from the estimated 87% he carried in 2020. Biden trails Trump among Hispanic voters, 39%-34%, way down from the 65% he polled in the first election.

Among voters under the age of 35, another group Democrats are counting on in 2024, Biden follows Trump by 37%-33%, according to the USA TODAY/Suffolk University Poll.

"Although Trump hasn't grown support among Black voters, he has closed the deficit because third-party voters come off of Biden's support among Blacks," said David Paleologos, director of Suffolk's Political Research Center. "A young voter or a person of color voting 'third party' is a vote away from President Biden, and a vote away from President Biden is a vote for Donald Trump."

From inflation to Israel: Addressing the issues on voters' minds

Biden also needs to convince voters that he is addressing problems that have driven down his poll numbers, particularly the economy (and inflation), immigration, the Israel-Hamas war and Russia's invasion of Ukraine.

Trump and other Republicans have constantly attacked Biden on all of these issues, and they may be fueling some political progress for the GOP.

An average of recent polls gives Trump 46.8% of the vote in a hypothetical matchup with Biden at 44.5%, according to Real Clear Politics. These results are within the margin of error, and voters are likely considering more than one issue as they evaluate the Democratic and Republican frontrunners.

In speeches and statements, Biden stresses that inflation is down, employment is up, and the economy is coming back from its COVID-induced setbacks.

"You know, when we started, the pandemic was raging, the economy was reeling," Biden told supporters in Maryland. "Because of you, look at what we’ve achieved: record job creation, historic economic growth, among the lowest inflation rates of any major economy on Earth."

Biden has also pushed for additional aid to Ukraine and Israel, telling Americans in an Oval Office address last year "I know these conflicts can seem far away, and it's natural to ask, why does this matter to America."

"Hamas and Putin represent different threats, but they share this in common: they both want to completely annihilate a neighboring democracy," Biden said.

Defining Donald Trump and Republicans

For months, Biden and Democratic officials have argued Trump is a threat to democracy. The president and his allies cite Trump's proposals to jack up presidential power and prosecute his political opponents.

But Biden hasn't limited his attacks to his predecessor. The incumbent president often refers to "MAGA Republicans" in general, a sign that he would redirect his attacks if another GOP candidate, such as former South Carolina Gov. Nikki Haley, manages to beat Trump for the party's presidential nomination.

"If we do our job in 2024," Biden said at the Maryland fundraiser, "we’ll be able to say something few generations get to say or have done: We’ll actually be able to say we saved American democracy.  Because the alternative is stark.  It is stark."

Democrats also note that Trump faces up to four criminal trials in 2024. Two of those cases accuse Trump of trying to steal the 2020 election from Biden, and another alleges he mishandled crucial classified documents.

"Trump's liabilities are ten times Biden's liabilities," Rosenberg said.

Lara Brown, a political scientist and author of "Jockeying for the American Presidency: The Political Opportunism of Aspirants," said Biden needs to travel the country to deliver his message and avoid a "Rose Garden strategy" based in the White House.

"It is time to ramp up his campaign, especially in the early primary states and the general election swing states, and start seeking the support from the voters that he will eventually need," Brown said.

Contributing: Susan Page, Rachel Looker and Miles J. Herszenhorn; USA TODAY