More likely that a lot more Americans just don't want to be associated with the extreme leftists in the Democratic Party. Obama, Pelosi, Reid and Frank are all pretty much way out there in left field with their political agendas. I'd say that only the really utopian minded Democrats can relate to the lies that those four produce as hope and change.
I can't say I blame the voters for wanting a balance of power. With the Democratic Party running the White House and both houses of Congress, the situation is dangerous. The Republicans blew their chance recently, but we need a certain amount of them in Congress to keep things under control. Before we know it, the Government will be controlling everything.
As the last paragraph said - Analysts say reasons may be dissatisfaction with Democrats or that Republicans who switched to vote in the 2008 Democratic presidential primary are returning to the GOP. I am more inclined to believe the latter since there were alot of R to D registration changes for the primary in 08. Talk radio around here really pushed for the change in registration to mess with the numbers.