California voters will confront a longer ballot with more choices as they head to the polls today for the first statewide primary featuring sweeping voter-approved election reforms.

A new top-two primary system and redrawn legislative and congressional districts are intended to blunt the influence of the two main political parties and lead to more competitive races involving more moderate candidates.

Today's voting will test those assumptions.

For the first time, an independent panel of citizens drew the boundaries for revamped legislative and congressional districts, and only the top two vote-getters in each race will advance to the November ballot, regardless of their political party.

That's likely

to create several hard-fought and expensive contests in the fall, including some that feature members of the same party and independents.

People registered to vote by mail already got a look at the new system when they opened their ballot and saw 24 candidates listed for U.S. Senate. Sen. Dianne Feinstein, a Democrat, is up for re-election this year but faces no serious challenger, despite the long roster of competitors.

While there is plenty of intrigue for political insiders, experts predict low voter turnout, likely less than 40 percent.

"I'm not worried about running out of ballots, if there's something good to be said about that," Contra Costa County Clerk Steve Weir said Monday. Election officials were also

coping with an unusual phenomenon for a June election in California - rain.

Some of the hottest contests are those in which candidates of the same party are vying to meet again in November.

Several incumbent Democrats are locked in heated contests against one another in two redrawn Los Angeles-area congressional districts. Reps. Janice Hahn and Laura Richardson have divided support, and Reps. Howard Berman and Brad Sherman are seeking to finish in the top two and move on to November. They were forced to compete against one another after the commission merged parts of the districts that each currently represents.

Nine of the state's 53 congressional districts have no incumbent on the ballot, and the open seats have lured dozens of contenders to those races. Democrats hope to pick up as many as six seats in California and have been working to register more voters in traditionally Republican-leaning areas of the Central Valley and the Inland Empire region of Southern California.

However, in the San Gabriel Valley and Whittier areas, the congressional races are not particularly competitive. Sitting Congress members are expected to prevail in the local primaries.

Democrats also are aiming to win a supermajority in the state Senate thanks to newly redrawn districts. But they are unlikely to cross that threshold in the Assembly, meaning tax and fee increases could not be passed without GOP votes.

Republicans are making runs at some incumbent Democrats. In the San Joaquin Valley, Ricky Gill, a well-financed 25-year-old who has attracted national attention, is challenging Rep. Jerry McNerney, who narrowly won the office in 2010.

Voters will decide just two ballot measures, after the Legislature passed a law saying all future initiatives must appear on general election ballots.

Proposition 28 asks voters if they want to alter California's legislative term limits, which were approved by voters in 1990. The measure would reduce the total number of years lawmakers can serve in the Legislature from 14 to 12, but it would allow them to serve all of that time in one house. The current term limits are among the strictest in the nation. Three, two-year terms can be served in the 80-member Assembly, and two, four-year terms in the 40-member Senate.

Voters also are being asked to add a $1-a-pack tax to cigarettes to help fund cancer research and anti-smoking campaigns.