California Code, Elections Code - ELEC § 6041

The Secretary of State shall place the name of a candidate upon the presidential primary ballot when the Secretary of State has determined that the candidate is generally advocated for or recognized throughout the United States or California as actively seeking the nomination of the Democratic Party for President of the United States.  The Secretary of State shall include as criteria for selecting candidates the fact of qualifying for funding under the Federal Elections Campaign Act of 1974, as amended.

On or before the 88th day preceding a presidential primary election, the Secretary of State shall publicly announce and distribute to the news media for publication a list of the selected candidates that the Secretary of State intends to place on the ballot at the following presidential primary election.