I think we are in an environment now where Congressional elections are more nationalized so it is harder for an individual incumbent to make the case that he is different from whatever people don't like about Congress.
I'm not sure how Democrats thought they could put up a liberal Speaker of the House from San Fransisco and a left-wing President from Chicago and expect that the rest of the country would just lie down and take it without a fight.
Obama is not anywhere as left wing as your making him ought to be.
