Filing for next year’s elections closed in California on Friday with a handful of late entrants setting the stage for competitive GOP primaries in the Senate and at least one open House seat.

In the marquee statewide matchup, former California Secretary of State Bill Jones jumped into the Republican field seeking to challenge Sen. Barbara Boxer, joining two other major GOP candidates as another dropped out of the contest.

On the House front, businesswoman Mary Ose (R) entered the already heated race to replace her brother, retiring Rep. Doug Ose (R), in the 3rd district. Farther south, colorful former Rep. Bob Dornan filed to challenge Rep. Dana Rohrabacher in the 46th district Republican primary.

Jones’ decision to run for the Senate, which had been expected for several weeks, led the news coming out of the Golden State. The GOP field already included ex-U.S. Treasurer Rosario Marin and former Los Altos Hills Mayor Toni Casey, but Jones is the only one of the three with a proven track record running statewide

State Assemblyman Tony Strickland (R) had planned to make the race but decided Friday not to run in the interest of party unity. Although Strickland will speak to all three candidates before making a decision, a California GOP source said he would likely endorse Jones.

“Jones clearly starts off as the frontrunner,” said a Republican official based in Washington. “The fact that he’s run and won statewide twice puts him a few steps ahead of everyone else who’s been in the race for a while.”

Jones, a farmer and former legislator from California’s Central Valley, was elected secretary of state in 1994 and narrowly re-elected in 1998. Last year, he came in a disappointing third in the GOP gubernatorial primary behind Richard Riordan and Bill Simon.

But given that the eventual race between Simon and then-Gov. Gray Davis (D) was close despite Simon’s missteps, some Golden State GOP operatives believe Jones would have won in November if he could have survived the primary.

A Field Poll taken in July showed Jones leading a Senate GOP primary test over Marin, Casey and Rep. Mary Bono but trailing Boxer by 12 points in a general election matchup.

Marin, Casey and Strickland have all been actively working to build support for several months, but last month’s recall election seems to have sucked enough of the political oxygen out of the state to prevent any of the three from gaining a real foothold with the public or the media.

As a Hispanic woman who supports abortion rights, Marin in particular has what many centrist Republicans consider to be the ideal profile for defeating Boxer, but she has yet to convince many GOP officials in either California or Washington, D.C., that she would be able to raise the $10 million to $20 million it could take to run a competitive race.

Avowedly moderate candidates have also had a difficult time winning statewide Republican primaries since ex-Gov. Pete Wilson (R) left office.

Republican observers in Washington and California said they expected both the White House and newly elected Gov. Arnold Schwarzenegger to remain neutral in the Senate primary. Jones supported Schwarzenegger during the recall vote and was also a high-profile backer of Sen. John McCain (R-Ariz.) in the 2000 presidential campaign.

Jones’ campaign team includes consultants Ed Rollins for general strategy and Larry McCarthy for media. Sean Walsh, who previously worked for Schwarzenegger’s campaign and for Wilson, will handle communications.

In the Sacramento-area 3rd district, Mary Ose enters a race that already features two strong GOP candidates — state Sen. Rico Oller and Dan Lungren, a former state attorney general and House Member.

Oller and Lungren have already worked hard to sew up endorsements from sitting lawmakers and from outside groups. Given her relatively late entry, Ose’s viability will likely depend on the extent to which she is willing to tap her own wealth and her brother’s willingness to aid her in fundraising.

As of press time, the only Democratic entrant was financial adviser Gabe Castillo. Assemblyman Darrell Steinberg (D) is not running.

The seat clearly leans Republican, and President Bush would have garnered 55 percent of the vote under the current lines.

In the 46th — based in Orange County and Southern Los Angeles County — Dornan is attempting for the second time to return to the House since 1996, when he lost his neighboring district to current Rep. Loretta Sanchez (D) in a disputed election. Rohrabacher challenged Sanchez in 1998 but lost by 17 points.

Republican Party officials said last week that they gave Dornan little chance of defeating Rohrabacher, who is popular in his district and has proven himself to be an adept fundraiser.

Dornan’s negative feelings toward Rohrabacher reportedly date back to the round of redistricting following the 1990 Census, when Dornan wanted his colleague to run in a neighboring district but Rohrabacher chose to remain where he was.

In 1998, Dornan and his family lashed out at Rohrabacher and Rep. Christopher Cox (R-Calif.), claiming they had lent insufficient support to his campaign against Sanchez that year.