LOS ANGELES — Three Democrats stood out from a crowd of 13 candidates as they seek spots in a run-off for an open seat in the California Assembly.

After early votes were counted Tuesday night in the special primary election to fill the seat representing northeastern Los Angeles, Mike Fong had a sizable lead with about 23 percent of votes.

That puts him nowhere near the 50 percent needed to claim the seat outright, and Fong appears headed to a December run-off.

In second place in the field with 10 of 13 Democrats is Luis Lopez, who has about 18 percent of the vote. He’s followed closely by Wendy Carrillo with about 17 percent.

The other ten candidates are running well behind.

Democrats are looking to bolster their supermajority in the Assembly, and it’s extremely likely two of them will emerge in the top slots once all the votes are counted, assuring them the seat.

“Democrats can’t lose, no matter who wins, no matter who ends up in the runoff,” said Jaime Regalado, former executive director of the Pat Brown Institute of Public Affairs at California State University.

California’s 51st Assembly District is one of the most solidly Democratic in the state, with a heavily Latino population and a large block of LGBT voters. No Republicans are running for the seat. The other three candidates represent the Libertarian Party, the Peace and Freedom Party or have no party preference, and all got only a handful of votes.

The seat was vacated this summer by now U.S. Rep. Jimmy Gomez. The Democrat was elected to Congress in a special election to replace Xavier Becerra, now California’s Attorney General.

A Democratic victory will again give the party 55 out of 80 Assembly seats — one over the threshold needed for a supermajority, giving the party power to pass tax and fee increases without Republicans. Democrats also hold a supermajority in the Senate.

Labor, LGBT and women’s groups are all playing in the contest, backing their favorite candidates.

Carrillo, for example, has the support of Emily’s List, a national organization that backs Democratic women, and the legislative Women’s Caucus. The Service Employees International Union also endorsed her.

Meanwhile, the LGBT group Equality California backed four candidates: Lopez, Alex de Ocampo, David Vela and Mark Vargas. All but Vargas are openly gay men.