SACRAMENTO -- The race for state controller, in which two Democrats are vying for second place, remained up in the air on Tuesday along with several other contests, a week after California's statewide primary.

Fresno Mayor Ashley Swearengin, a Republican, sealed the top spot in the controller's contest but does not yet know who she will face in November. Former Assembly Speaker John Perez had only a few hundred votes over Board of Equalization member Betty Yee.

Under California's new primary system, the top two vote-getters advance to the general election regardless of party affiliation.

County clerks estimate that as many as 756,000 ballots remained uncounted statewide.

The challengers for as many as four U.S. House races and up to five state legislative races also remained undetermined, according to reports filed with the secretary of state's office.

It was unclear who will challenge Democratic Rep. Eric Swalwell in the 15th Congressional District, where only a few hundred votes separate state Sen. Ellen Corbett, a Democrat from Hayward, and Hugh Bussell, a Republican from Dublin, for second place.

In the 24th Congressional District, incumbent Democrat Lois Capps will likely face a Republican, but only a few hundred votes separate Justin Donald Fareed and Chris Mitchum, son of actor Robert Mitchum, for second place.

In the San Bernardino-area's 31st Congressional District, Democrats were hoping to take control of the seat after the retirement of Republican Rep. Gary Miller. But Iraq War veteran and security consultant Paul Chabot, a Republican, advanced to the runoff, with Democrat Pete Aguilar only a few hundred votes ahead of Republican Lesli Gooch for the second spot on the November ballot.

In the Legislature, the margin in five contests was within 2 percentage points.

The open Southern California seat of Democratic Sen. Ted Lieu, who is running for Congress, will feature two Republicans in November: Jeff Stone, who finished as the top vote-getter, and either former state lawmaker Bonnie Garcia or Glenn A. Miller. Garcia declared victory on Friday but is ahead by only a few hundred votes.

Fewer than 1,000 votes separate a Republican and two Democrats in the Sacramento-area seat being vacated by Assemblywoman Mariko Yamada, a Democrat. Republican Charlie Schaupp was leading in the 4th district, with Democrats Bill Dodd and Dan Wolk close behind.

In the attorney general's race, incumbent Democrat Kamala Harris easily advanced and is likely to face Republican Ronald Gold, who currently has a 32,000-vote lead over fellow Republican Phil Wyman.

A secessionist movement in Tehama County passed with about 56 percent of the vote, allowing local officials to begin working with four other counties that are considering forming a new state called Jefferson. Only a few hundred ballots remained to be counted, not enough to change the outcome.

Some of the tight races could be headed for recounts, which can take weeks.

Any registered voter can request a recount but they must be willing to pay the cost, which is refunded if the outcome of the race changes after the tally.