No PK, its the radiation in the salmon.
Just keep in mind once you get out of the major metropolitan area's like Seattle, Portland, San Francisco, Los Angeles the folks are conservative.
Los Angeles is boxed in by the Pacific to the West, mountain passes and high population to the North, mountain passes, arid desert and Mexico to the South, and mountain passes and arid desert to the east. Cut off their water supply from the Sierra Nevada mountains and they are out of the game.
San Francisco is an island and the only really problem would be getting the libs in Oakland to fall back to S.F. Once they do, let the siege commence and get on w our lives while they slowly die.
Worst case take out the power grid and the coastal populations turn on each other while the Sierra Nevadas act as a natural barrier from the chaos.