Oleg, my theory for that phenomenon is that state elections are coveredby state and local press to a bigger extent than by national liberalpress. People get heavier assault by the biased national press duringpresidential elections.
and I also have a different take on this kind of phenomena..it all depends on the state population too...like it was explained to me by someone from SD, where a large portion of population is of German dissent, and Germans have a strong sense of socialism...so they vote democrat for Senate/House (because they love farm subsidies, and republican for President (because they favor strong national security)..