California is a heavily blue state, but most of the Democrats live on the coast, while Republicans tend to live in the interior part of the state.
And:
Since Democratic candidates have carried California in the last four presidential elections, and are heavily favored to do so again in 2008, the goal of the ballot drive is to shift 20 or more of the state’s 55 electoral votes to the losing Republican, making it more likely that in a close national vote a Republican who loses the popular vote could still win the Electoral College, as Bush did in 2000 after the Supreme Court awarded him Florida’s electoral votes.
