Former Vice President Joe BidenJoe BidenHaiti prime minister warns inequality will cause migration to continue Pelosi: House must pass 3 major pieces of spending legislation this week Erdoğan says Turkey plans to buy another Russian defense system MORE will officially enter the presidential race on Thursday, according to a source close to his campaign.
Biden has been flirting with entering the race for months and will begin his campaign in the lead in several surveys nationally and in early-voting states.
Biden will announce his candidacy with a video released on Thursday and then will travel to Pittsburgh for a more formal event on Monday, the source said.
Biden, who would be 78 when entering the Oval Office if he wins the presidency, faces a crowded field and a number of questions about his candidacy.
A new poll from Monmouth University released Tuesday found Biden leading Democratic candidates and winning 27 percent support nationally, 7 points higher than the 20 percent won by Sen. Bernie SandersBernie SandersIn Washington, the road almost never taken Don't let partisan politics impede Texas' economic recovery The Hill's Morning Report - Presented by Alibaba - Democrats argue price before policy amid scramble MORE (I-Vt.).
Sanders may be the top competition in the race for Biden initially. A series of polls have had the two bunched together at the top, with some distance from other candidates.
Biden will face questions about whether he is liberal enough to win his party's nomination.
There have been questions already about his support for a Clinton-era crime bill and his backing for the Iraq War.
Biden also is dealing with a lingering controversy involving his touching and kissing of a number of women, several of whom said it was inappropriate.
Biden's campaign is expected to argue he is the Democrat most likely to defeat President TrumpDonald TrumpGraham says he hopes that Trump runs again Trump says Stacey Abrams 'might be better than existing governor' Kemp Executive privilege fight poses hurdles for Trump MORE in the general election.