Terry McAuliffe, former Virginia governor, will begin a bid for his old job.

Terry McAuliffe, the former governor of Virginia, will enter the contest for his old job on Wednesday, according to a person familiar with his plans, joining an already crowded Democratic primary that is likely to serve as a harbinger of the party’s future.

Mr. McAuliffe, 63, will formally start his campaign in Richmond, the state capital, surrounded by three senior elected officials, all of whom are Black. The plan is a nod to the relationships he nurtured during his governorship from 2014-18 and the complex nature of the 2021 primary, in which three other Black candidates have already announced their candidacies for the Democratic nomination.

Mr. McAuliffe will center his campaign around helping the state’s economy recover from the effects of the coronavirus pandemic, pledging Virginia’s largest investment in public education and appealing to Black voters in the Democratic primary in June. The themes are similar to those that propelled President-elect Joseph R. Biden Jr. to the Democratic Party’s nomination and then the White House.

But it remains unclear whether Virginia Democrats, after Mr. Biden’s victory, are looking for a carbon copy. Three candidates have been campaigning for months: Jennifer McClellan, a state senator; Jennifer Carroll Foy, who on Tuesday resigned her seat in the House of Delegates to campaign for governor full time; and Lt. Gov. Justin Fairfax.

The Republican field for governor includes Kirk Cox, a former speaker of the House of Delegates. Amanda Chase, a Republican state senator who models herself after President Trump, said this weekend that she would run as an independent candidate rather than seek the Republican Party’s nomination at a state convention next year — a development that could fracture the Republican vote in the general election.

Mr. McAuliffe is a longtime fixture in Democratic politics, both nationally and in Virginia. He is close enough to former President Bill Clinton that the two men speak daily. A former Democratic National Committee chairman, Mr. McAuliffe has run for Virginia governor twice, losing in a 2009 primary before winning in 2013. He also weighed a 2020 presidential campaign but bowed out in April 2019 once it became clear that Mr. Biden would seek the Democratic Party’s nomination.

Virginia’s current governor, the Democrat Ralph Northam, is forbidden by state law from seeking a second consecutive term. Mr. McAuliffe is vying to be the second Virginia governor since the Civil War to be elected twice.