SAN FRANCISCO (AP) -- Two veteran Republican lawmakers were facing a widening gap in their battles against Democratic rivals as election officials tallied up more late votes for several congressional races that were still too close to call Friday afternoon.
Of the three U.S. House contests in California that remained undeclared, Republican Rep. Mary Bono Mack had the largest margin to make up of any Republican incumbent against her Democratic challenger, Raul Ruiz. As of Friday afternoon, she trailed Ruiz by 4,679 votes, out of 166,000 counted Friday in their heated congressional race in the desert communities surrounding Palm Springs.
In the Sacramento area, GOP Rep. Dan Lungren was struggling to fend off Democratic physician Ami Bera, who increased his lead slightly late Friday in their still-undecided race.
The latest vote tallies released by elections officials Friday showed Bera leading by nearly 1 percentage point. He was 1,779 votes ahead with 208,000 votes counted. Elections officials said there were still about 100,000 votes to be counted in Sacramento County, but it was unclear how many of those fell within the 7th Congressional District.
In San Diego, GOP Rep. Brian Bilbray's race against Democratic challenger Scott Peters was still a tossup Friday. Bilbray was behind by 814 votes out of 210,000 counted.
County officials were still counting millions of mail-in and provisional ballots statewide three days after the election, and all campaigns were poised for any new announcements about the latest tallies of mail-in and provisional votes.
In Riverside County, elections officials had about 164,000 ballots left to count. San Diego County estimated about 375,000 left to count, while Sacramento County reported working through the 193,000 ballots it had left.
California's congressional races have grown much more competitive since an independent panel redrew the district boundaries in 2010, the same year the U.S. Supreme Court struck down limits on outside political spending.
State congressional races drew intense interest nationally, after gerrymandered strongholds were transformed into free-for-alls rich with campaign cash from groups as varied as Planned Parenthood and Americans for Tax Reform, headed by low-tax crusader Grover Norquist.
Super PACs and other outside groups flooded California's House races with more money than any other state under new rules allowing unrestricted outside political spending. By Tuesday, spending had reached nearly $54 million, according to the Center for Responsive Politics.
County registrars have 28 days after the election to finalize results under California law, but any candidate or voter can ask for a recount within the following five days. Should that occur, local elections officials can appoint four voters to oversee a special recount board, a process that could take weeks to finalize.