Mary Ose (search) wants to follow in her brother's footsteps by running for the California House seat he is vacating at the end of this term. She insists she has a different style from her brother, but she is willing to fight a tough and expensive primary to prove voters will like it.

"I stand on my own two feet," said Ose, who announced in December that she would be running to fill the 3rd district seat in the greater Sacramento area now held by her brother, Rep. Doug Ose (search), R-Calif.

"I'm as proud as anyone can be of my brother. He's one of my biggest fans," she told Foxnews.com. "But we're not identical, and we wouldn't make all of the same decisions."

But like her brother, Ose is a moderate Republican — conservative on the fiscal issues, more liberal on the social ones. She says her love and loyalty to the community come from a lifetime of living and doing business in the district.

Also like her sibling, she has made millions of dollars in the real estate business, and is willing to put up her own money to win the seat.

And she may just have to, say political analysts, who note that Ose has jumped into a serious Republican battleground, which includes Dan Lungren (search), a former U.S. representative and eight-year state attorney general; state Sen. Thomas "Rico" Oller (search), whose constituency makes up about 70 percent of the congressional district; and engineer Rick Frankhuizen (search).

Nearly 80 percent of the third district population lives in Sacramento County. Aside from being the seat of the state government, greater Sacramento was until recently flourishing farm country. It now is a burgeoning metro center with a growing real estate market and private sector business hub. Its residents voted 55 percent for George Bush in the 2000 election.

Given the Republican-leaning nature of the district, the March 2 primary could very well decide the entire race, said Nathan Gonzales, an analyst for the Rothenberg Political Report (search).

"We expect the real race to be played out in the Republican primary," Gonzales said, noting that the Political Report is giving a "slight advantage" to Oller, who has garnered the early support of the National Rifle Association and the Club for Growth (search).

Asked about Ose's entrance into the race, Oller, a businessman who has been in office since 2000 and notes immigration and tough border control among the key issues for his constituency, predicted it will hurt Lungren rather than himself.

"I am clearly the definite conservative in this race and this district is probably 70 percent of people who define themselves as conservative," Oller told Foxnews.com. "That leaves a small percent of voters who will split their vote between Lungren and Ose."

Lungren has two major vulnerabilities, political observers say. He lost a tough and very expensive bid for governor against Democrat Gray Davis in 1998, and he has not been in the community as long as the other candidates. In fact, when he served in the U.S. Congress from 1978 to 1988, he represented Long Beach, in southern California.

Lungren does, however, boast a growing list of congressional endorsements, nearly 15 as of Jan. 9. He told Foxnews.com, that unlike his opponents, his wide experience in criminal justice, courts and border issues sets him apart.

"I could start working from day one in helping the district  — I have no learning curve," said Lungren.

As California attorney general during the 1990s, Lungren helped to revive the state's death penalty and bring down the crime rate, in part by sponsoring the "three-strikes-you're-out" law that slapped repeat offenders with stiff prison sentences.

"Experience that has resulted in true performance marks my candidacy," he said.

"Dan Lungren is, by far, the most qualified candidate to represent California’s 3rd Congressional District,” said Rep. Bill Thomas (search), R-Calif., chairman of the House Ways and Means Committee.

Ose has received her share of support, too, specifically from the Republican Main Street Partnership (search), a coalition of moderate congressional Republicans.

"Mary Ose is not a career politician," said executive director Sarah Chamberlain Resnick.

But Ose does have strong experience in the business community, she added. "She will be a reliable voice for lower taxes, eliminating government waste and reducing the budget deficit."

Frankhuizen, who ran unsuccessfully against Rep. Robert Matsui (search), D-Calif., in the neighboring 5th district in 2002, said he knows he's a long shot, but believes a moderate has a much better chance of capturing the votes in this district than a far-right conservative.

"For me, its not where a candidate falls on the political spectrum," he said. "But looking at their personalities, it's how they work with the other members of the California congressional delegation. They need to ask, can I be in conversation with people of different views and opinions? Or will I stand in continual debate and produce nothing?"

Frankhuizen said Rep. Ose is popular because he was viewed as an active member of the community —"he was always available.

"His sister appears to have similar characteristics," he added. "I really like her as a person and I believe she brings a particular contribution to this race."

Gabe Castillo (search), the only Democrat in the race, said he is undeterred by the fact that the district has been trending Republican over the last 15 years. He said it's where candidates stand on the issues right now, not what party label they carry.

He calls himself a conservative Democrat concerned with "kitchen table issues," such as job loss in the area, health care and protecting the middle class. At this time, he prefers spreading this message, and watching the fireworks on the other side of the political aisle.

"I'm awfully glad I'm not a Republican right now," he said. "It's a tough field."