Northern California, Oregon, and Washington are possible. San Francisco is the capital of the American counterculture and green movements, Oregon has the whole "State of Jefferson" thing in its 20th century past, and Eastern Oregon and Washington are, to generalize, chock-full of anti-government militia types, by reputation anyway.
Oregon and Washington also seem to have a lot of left-of-Democrat Democrats and progressives and right-of-Republican Republicans and libertarians/constitutionalists.
Anyway, maybe Jerry Brown stops running for President, runs for a third term as governor instead of trying to become a Senator, and uses his influence as California Democratic Party chairman to transform the state-level party into one more in line with the leftist, green, and other counter-cultural movements he drew support from in OTL. Term limits weren't enacted in OTL in California until 1990, so, if he can keep getting elected, he could theoretically continue being governor up and beyond 2012, considering OTL's Jerry Brown is still alive and kicking.
The West Coast being seen as that crazy place that has had the American ATL equivalent of OTL's Hugo Chavez in power "since forever" could help drive a wedge, as could Brown directing his condemnation at the Reagan Administration rather than his Democratic Party rivals. Heck, Brown continuing to be Governor throughout the eighties could lead to some jurisdictional back-biting, a "war" if you will between the state of California and the federal government. It would have to hurt if all throughout his two terms in office Reagan had to deal with the governor of his own state constantly harangue him and act as the national voice of opposition to him.
Forming some sort of regional rather than party-based governors association with the governors of Oregon and Washington would also help.