The latest Report of Registration released by the Secretary of State's office shows that 20.1 percent of voters have declined to state their political party, an all-time high.
This is up 2 percent since the same time before the last gubernatorial primary election. Democratic Party registration has increased from 42.7 percent in 2006 to 44.6 percent, while Republican Party registration has decreased from 34.6 percent to 30.8 percent.
Primary voters will decide who the gubernatorial nominees for each party will be, decide if five state ballot measures will become law, and decide other local issues.
California's primary system allows each political party to decide whether to allow decline-to-state voters to vote in their primary. The Democratic and Republican parties will allow decline-to-state voters to vote on their ballots in the primary, but the other four registered parties will not.
There are currently 16.9 million Californians registered as voters, up 1.3 million from this time four years ago. The deadline to register to vote is May 24. The last day to request a vote-by-mail ballot is June 1.