SAN FRANCISCO - MAY 25: Members of the Tea Party movement protest outside the Fairmont Hotel before U.S. President Barack Obama arrives for a fundraiser May 25, 2010 in San Francisco, California. Hundreds of protestors from different political groups staged the demonstration at a campaign fundraiser for U.S. Sen. Barbara Boxer (D-CA). (Photo by Justin Sullivan/Getty Images)
As the November election approaches, California's tea party groups are backing Republican candidates almost exclusively.
Despite the movement's nonpartisan label, its endorsements and fundraising activities have overwhelmingly targeted highly conservative GOP challengers seeking state legislative and congressional seats.
Formal polls and casual surveys at tea party events help explain this preference: the vast majority of tea party activists are themselves Republicans or independents who vote Republican.
But both insiders and observers agree that the tea party's success in getting its chosen candidates elected will hinge on its ability to win over voters from outside the GOP's reliable base.