Just 456 votes separate two Laguna Beach Democrats vying to face off against longtime Rep. Dana Rohrabacher in the November general election for Rohrabacher’s 48th Congressional District seat, according to the latest count from the June 5 primary election.

As of late Tuesday afternoon, scientist and stem cell researcher Hans Keirstead had pulled in 17.3% of the votes cast, while attorney and businessman Harley Rouda was nipping at his heels with 17%.

The two have been running essentially neck and neck since the polls closed. A previous update over the weekend showed Keirstead ahead of Rouda by 87 votes.

The Orange County Registrar of Voters office estimated there are still more than 107,000 ballots left to tally countywide.

The top two vote-getters in the primary advance to the Nov. 6 election. Rohrabacher (R-Costa Mesa) already secured a spot with more than 30% of the vote.

Sitting behind Keirstead and Rouda is Republican Scott Baugh, who had 16.2% of the vote as of the latest tally. He has already conceded the race and endorsed Rohrabacher for the fall election.

All of the 12 other candidates on the primary ballot received less than 5% of the vote, figures show.

Democrats have targeted the 48th District seat, which Rohrabacher has held for 15 terms, as a potential pickup throughout this election cycle. The district includes Costa Mesa, Fountain Valley, Huntington Beach, Laguna Beach and Newport Beach.

Other races

The other local races on last week’s primary ballot don’t have the too-close-to-call intrigue of the congressional contest.

In the 72nd Assembly District, which includes Fountain Valley and a portion of Huntington Beach, Democrat Josh Lowenthal and Republican Tyler Diep advanced to the general election.

In the race for the 74th Assembly District seat representing Costa Mesa, Laguna Beach, Newport Beach and part of Huntington Beach, incumbent Matthew Harper (R-Huntington Beach) will seek his third term against Democrat Cottie Petrie-Norris.

Orange County Supervisor Michelle Steel, a Republican, won 64% of the vote, securing reelection to represent the Second District, which includes Costa Mesa, Fountain Valley, Huntington Beach and Newport Beach.

luke.money@latimes.com

Twitter @LukeMMoney

UPDATES:

5:15 p.m.: This article was updated with the latest vote count.

This article was originally published at 2:50 p.m.