If you want to have an impact on who becomes Chair of the DNC, it is probably time to start lobbying. The DNC is composed of 440 members. Each state (plus DC and Puerto Rico) gets to send its Chair and the highest-ranking officer of the opposite sex (typically the Vice Chair). Territories and Democrats Abroad also get this allocation. This accounts for (yup, you guessed it) 112 members. An additional 200 are distributed among the states and territories based on population, with each jurisdiction receiving at least two additional members. California's delegation is listed on its state party website:
Female
Rachel Binah
Mary Ellen Early
Inola Henry
Alice Huffman
Aleita Huguenin
Carole Migden
Christine Pelosi
Alicia Wang
Maxine Waters
Rosalind Wyman
Male
Steven K. Alari
Ed Espinoza
Bob Mulholland
John Perez
Robert "Big Red" Rankin
Garry Shay
Christopher Stampolis
Keith Umemoto
Steven Ybarra
No email addresses are provided. That gets us to 312 members.
Constituency groups also have representatives to the DNC. Two Senators and two Representatives serve on the DNC. Two College Democrats. Three Governors, three mayors, three legislators, three county officials, three municipal officials, three Young Democrats, and three people from the National Federation of Democratic Women. From what I can tell, this gets us to 339. 50 members are appointed by the DNC Chair and are considered members-at-large. I don't know where to find the names of these people. This seems like a good use of the dKosopedia, though I am unfamiliar enough with it that I don't want to start that project.
Individual people tracking down contact info for the National Committeemen and women from their state and constituency groups, as well as the national ones we can all contact is another way to help breed support as well as let us ID who is leaning which way for which candidate for chair.