SAN FRANCISCO (KRON) – State Assemblyman Kevin Mullin (D-San Mateo) and San Mateo County Supervisor David Canepa are leading the race to head to November’s election for the US House of Representatives seat representing the 15th district of California, covering southern San Francisco and much of the Peninsula.

Mullin won 40.0% of voters, and Canepa 24.5%, with 71% of precincts reporting, according to preliminary election returns as of early Wednesday. Republican Gus Mattammal, a private tutor, follows close behind Canepa with 17.8%.

They are running to replace Rep. Jackie Speier (D-San Mateo), who is not running again. Speier, 72, was first elected in 2008 after serving in the California State Senate. She replaced Rep. Tom Lantos, who died in office.

The 22nd Assembly District, which Mullin represents, moved due to redistricting from the Peninsula to the San Joaquin Valley. Speier and other Democratic leaders endorsed him. Canepa represents District 5, including Daly City, Colma, Broadmoor and Brisbane, and parts of San Bruno and South San Francisco, on the county level.