Factbox-Biden's lone challenger for the Democratic presidential nomination

(Reuters) - U.S. President Joe Biden, who took office in early 2021, faces little opposition in his bid for the Democratic Party nomination in the 2024 presidential election.

With former President Donald Trump the frontrunner in the Republican Party's nominating race, Biden's strong position in the Democratic primary sets up a likely repeat of the 2020 presidential election battle with a potentially tight rematch.

Here are the candidates running to be the Democratic nominee:

JOE BIDEN

Biden, 81, already the oldest U.S. president ever, will have to convince voters he has the stamina for another four years in office, amid poor approval ratings and a special counsel report suggesting he suffered memory lapses. Biden has blasted the report, and his allies say he believes he is the only Democratic candidate who can defeat Trump and protect democracy. The most recent Reuters/Ipsos poll put Biden at 34%, while Trump garnered 37% — close to the 2.9 percentage-point margin of error.

In announcing his candidacy, Biden declared he needed to defend American liberties and pointed to the deadly Jan. 6, 2021, attack on the U.S. Capitol by Trump supporters. Vice President Kamala Harris is again his running mate.

The economy will also factor in his reelection campaign. While the U.S. escaped an anticipated recession and is growing faster than economists expected, inflation hit 40-year highs in 2022 and the cost of essentials is weighing on voters. Biden pushed through massive economic stimulus and infrastructure spending packages to boost U.S. industrial output, but he has received little recognition from voters for the latter.

Biden has led the response of Western governments to Russia's invasion of Ukraine, persuading allies to sanction Russia and support Kyiv, and he has been supportive of Israel in its conflict with Hamas militants in Gaza while pushing for more humanitarian aid. However, he has faced sharp criticism from some within his party for not backing a ceasefire in the Palestinian territory, where Gaza health officials say more than 28,400 people have been killed, thousands of buildings have been damaged or destroyed, and residents have insufficient food, water and medical supplies.

Biden's handling of immigration policy has also been criticized by Republicans and Democrats as migrant crossings at the U.S.-Mexico border hit record highs during his administration.

In the Democratic Party's presidential nominating contests, Biden has easily won in New Hampshire, South Carolina and  Nevada.

DEAN PHILLIPS

Dean Phillips, a little-known U.S. congressman from Minnesota, announced in October he would mount a long-shot challenge to Biden because he does not believe the president can win another term.

The 55-year-old millionaire businessman and gelato company co-founder announced his bid in a one-minute video posted online, saying: "We've got some challenges. ... We're going to repair this economy, and we are going to repair America."

Phillips failed to win any delegates in South Carolina and took second place in New Hampshire. He did not appear on the Nevada ballot.

(Reporting by Costas Pitas; Editing by Jonathan Oatis and Lisa Shumaker)