Rep. John Garamendi (D-Walnut Creek) vs. Kim Vann (R)
Democrats' relatively slim 9-point registration advantage made the 3rd District an attractive target for Republicans. More than three-fourths of voters there are new to Garamendi.
Rep. Dan Lungren (R-Gold River) vs. Ami Bera (D)
Outside groups have spent more in this 7th District race than the candidates together have raised. Registration is nearly evenly divided.
Rep. Jerry McNerney (D-Pleasanton) vs. Ricky Gill (R)
Young law school graduate Gill's impressive fundraising boosted Republican hopes in the 9th District, which tilts Democratic.
Rep. Jeff Denham (R-Modesto) vs. Jose Hernandez (D)
Democratic leaders encouraged former NASA astronaut Hernandez to run in the 10th District. Both parties have spent lavishly here.
Rep. Lois Capps (D-Santa Barbara) vs. Abel Maldonado (R)
National Republicans lined up early behind former lieutenant governor and legislator Maldonado. The newly drawn 24th District put the popular Capps in a rare fight.
SOUTHERN CALIFORNIA COAST
Assemblywoman Julia Brownley (D-Oak Park) vs. state Sen. Tony Strickland (R-Moorpark)
This contest in Ventura County is a classic two-party dustup. The district is the 26th.
Gary DeLong (R) vs. state Sen. Alan Lowenthal (D-Long Beach)
Democrats have an 13-point registration edge in the 47th District, which stretches from Long Beach into Orange County. Republicans hope DeLong's moderate views will attract nonpartisan voters.
Rep. Brian P. Bilbray (R-Carlsbad) vs. Scott Peters (D)
Both parties and some well-heeled outside interests are battling hard over the 52nd District in San Diego County. More than a quarter of voters are unaffiliated.
Rep. Mary Bono Mack (R-Palm Springs) vs. Raul Ruiz (D)
Shifting demographics have given Democrats hope of unseating Bono Mack in the GOP-leaning 36th District, where registration is nearly evenly divided.
Mark Takano (D) vs. John Tavaglione (R)
National Republicans are betting on the moderate Tavaglione, a county supervisor, in the 41st District, even though Democrats have a slim membership edge.
Source: California secretary of state's office, Times reporting