Supporters say the measure will promote consistency and reduce the influence of lobbyists. Critics warned the change would lead to entrenchment in the state Capitol.
Democratic U.S. Sen. Dianne Feinstein easily won her primary election race. She advanced to the November ballot, where she will face GOP-endorsed autism activist Elizabeth Emken.
Congressmen Brad Sherman and Howard Berman, both Democrats, will head to a November showdown for the San Fernando Valley's 30th Congressional District. Sherman grabbed about 40 percent of the vote, to 34 percent for Berman, with 18 percent of precincts reporting. Several Republicans trailed far back. The two incumbents were pitted against each other because of redistricting. They had previously represented two separate congressional districts.
Presidential hopeful Mitt Romney swept the five states holding GOP presidential primaries - California, New Jersey, South Dakota, New Mexico and Montana. Romney and Democratic President Barack Obama already have won enough delegates to claim their parties' nominations.
Californians were casting their ballots in the state's first open top-two primary. The top-two voting system meant voters did not have to belong to a certain political party in order to cast a ballot for congressional, legislative and statewide races. They still select one candidate for each office on their ballot. The first- and second-place winners, regardless of party, will move on to the November general election, except in the case of the presidential central committee and local races.
The idea of a top-two primary is to help elect more moderate people to the legislature and other non-presidential offices to end gridlock, especially in Sacramento, by electing lawmakers who are more willing to compromise. Critics say the new system could result in candidates from the same party being the top two.
Meantime, a couple of high-profile propositions on the ballot will be closely watched. Proposition 29 would slap an additional $1 per pack tax on cigarettes and other tobacco products. The money would go toward funding anti-smoking programs and cancer research.
California is one of only a few states that has not hiked its cigarette tax in the last decade. If Prop. 29 passes, California would have the 16th-highest tax rate in the nation at $1.87 per pack. The tobacco industry has spent millions of dollars fighting the measure, calling it flawed.
For Proposition 28, voters were asked whether they want to change California's legislative term limits. The measure would reduce the total number of years lawmakers can serve in the legislature from 14 to 12, but all of that in one house.
Lawmakers were allowed to do six years in the Assembly and eight years in the state Senate. It was common for a member of the Assembly to start campaigning for Senate before their term was finished. Critics warned the change would lead to entrenchment in the state Capitol.
Voter turnout for Tuesday's primary was expected to be below 40 percent. Democrats make up the largest share of registered California voters, with 43 percent. Thirty percent are Republicans and 21 percent have no party affiliation.
According to the Los Angeles County Registrar-Recorder, by 5 p.m. about 17.5 percent of registered voters cast a ballot. That was up slightly from 14.1 percent in 2010.
Some voters said they were disappointed by the low turnout at the polls.
"One of the things that's unique and different about it is having a voice," said Barbara Younker of Pasadena, "and yet it doesn't make it unique and different unless you express that voice."
Polls were open from 7 a.m. to 8 p.m.