President Barack Obama will be the Democratic nominee for president. Former Massachusetts Governor Mitt Romney is the presumptive Republican nominee challenging him.
But when Californians vote in the June 5 primary election, they don't have to belong to a political party to pick a nominee for congressional, legislative and statewide races.
Voters still get one vote for each office, but the first- and second-place winners, regardless of party, move on to the November general election.
"This change is going to give millions of California voters more of a say in the voting process, more power to decide who the candidates and the ultimate winner will be in political districts up and down the state," said Kim Alexander, founder and president of the California Voter Foundation. "This new process really shakes things up a lot."
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.
The new system also aims to lessen the power that party leaders have over which candidate gets to be the nominee.
But opponents say the top-two primary system could result in two candidates from the same party vying for one office, leaving little chance for smaller, less-funded parties to win.
Critics also point out it doesn't work in Washington state.
"The Washington State Legislature this year, which all was elected in the top-two system, was not able to pass the budget during the regular session," said Richard Winger, editor of Ballot Access News. "The governor had to call a special session. They still couldn't pass the budget."
It's too early to tell whether more moderates will win office. New political districts lines drawn by a citizens commission could also help, but big money may still be too influential.
"In the end, you do need the money and the endorsements of major groups up and down the state and the groups themselves are somewhat polarized," said Prof. Bruce Cain, director of the University of California Washington Center.