There are more details in this story from the LA Times, “Number of California voters reaches record levels.” Readers of our blog will likely be interested in how the new online registration system in California has influenced this:

More than 1.4 million new voters have signed up, nearly 50% of them online under a new law that kicked in six weeks ago allowing electronic registration. They tend to be younger and more left-leaning than the state’s general voting population, according to Political Data Inc., a bipartisan firm that analyzed county reports.