The California Rules

On Feb. 5, California will almost certainly hold its most influential presidential primary in a generation. But it will not be using the statewide winner-take-all format that gave the Golden State primary much of its dramatic win-or-else quality in the 1960s. California Democrats switched to proportional representation long ago, while the Republicans are trying a modified version of winner-take-all in 2008. Under the new format, the GOP winner in each of the state's 53 congressional districts will win three delegates, while a small bloc of at-large delegates are to go to the statewide winner.

California Republicans will hold a closed primary in which only registered Republicans can participate. the Democratic primary, however, will be open to registered independents (or "Decline to State," in California parlance) in addition to registered Democrats. As of February 2007, there were 15,682,358 registered voters in California—6,667,437 Democrats, 5,362,473 Republicans, 2,953,414 independents, and 699,034 voters registered with third parties.