The current occupant of the seat, Assemblyman Guy Houston (R., San Ramon), is now in his third term and must leave the position in January due to term limits.
The Democrats running are Joan Buchanan of Alamo, vice president of the San Ramon Valley School Board; and Theodore Ford, an economist from Walnut Creek.
On the republican side are Judy Lloyd of Danville, a former Reagan administration member; and San Ramon Mayor H. Abram Wilson.
Judy Lloyd was appointed to the U.S. Department of Agriculture by President Reagan. She was also an assistant to Bob Dole when he was the Senate Majority Leader; a special projects director for the Republican National Committee; and co-chairwoman of Arnold Schwarzenegger's campaign for governor.
"I've been involved with the Republican Party for 25 years," she said. "I've had the opportunity to work with some of the great leaders."
Education, the budget, the economy and immigration are important issues to Lloyd, she said. She is concerned that the Democrats in the state legislature are averse to change, squandering taxpayer dollars and creating a budget deficiency.
"We need somebody that's going to be strong up there to fix a broken system," she said.
Mayor H. Abram Wilson has served on the San Ramon City Council since 1999. He became the city's first elected mayor in 2003 and was re-elected in 2005 and 2007.
A veteran himself, Wilson serves on the board of the Iraq veteran's organization Sentinels of Freedom. He's also on the foundation board of directors for Diablo Valley College, and has been a member of the San Ramon Arts Council for 10 years.
Democratic candidate Joan Buchanan has served for 20 years on the San Ramon Valley School Board, including four terms as president. She was president of the Alamo Elementary School PTA, and vice president of the San Ramon Valley School Age Child Care Alliance.
Besides education, Buchanan is an advocate for universal healthcare and is focused on the environment. She said traffic and affordable housing are also areas of concern for residents throughout the 15th District.
She said she is running because, "One: I'm ready for a new challenge. And two: I think I'm the best person to represent the values of the people in the 15th District."
The other democratic candidate, Theodore Ford, said his main focus is on "the unbalanced fiscal structure" in the area. He said this underlying issue affects education and everything else.
Ford has worked for 35 years as an economist in both government and the public sector. He has never run for electoral office, but the 12-year Walnut Creek resident called himself "an observer of the political current."
"The reason I got into the race was because of my strong feelings about these issues and wanting to address them in a public forum," said Ford. "It would be nice if a citizen candidate could go out there and articulate a point of view that resonates with people and get some votes."
"We'll see how it turns out," he added. "I'd like to win."
Buchanan, Lloyd and Ford all mentioned the Sacramento-San Joaquin Delta, which is mainly located in the 15th District. The Delta provides the water for two-thirds of California and is in a tenuous situation.
California's 15th District includes Danville, Alamo, Walnut Creek, San Ramon, Livermore, Brentwood, Discovery Bay, part of Pleasanton, and portions of the Sacramento Delta communities of Stockton, Galt and Elk Grove.
It is generally considered a swing district - the voters are split nearly 50/50 by party. Both Republicans and Democrats feel they have a good chance to win this year's election.
"It's one of the top three targeted districts in the state," Buchanan said. "So this will be a very exciting election."
Political makeup of District 15
Total registered voters: 164,902
Democrats: 63,897 - 38.7%
Republicans: 64,566 - 39.1%
Declined to state: 30,476 - 18.5%
Source: Contra Costa County Elections Department