What has been inexcusable and irresponsible has been the Obama Administration's general reluctance to fight for the issues they campaigned on.
There have been victories, like Health Care Reform, but even those were fought for hesitantly. From issues like helping the middle class, restoring reasonable taxation on the richest 1% of the nation, war, economic recovery, and I could go on (judges), the Administration has ceded the battleground to Radical Republicans, frequently surrendering without firing a shot.
The apathy the Administration has noticed in the public is simply a reflection of the apathy the public has noticed in the Administration.
All that said, if Republicans like Rand Paul, Sharron Angle, and Christine O'Donnell gain leadership posts in the Senate then this nation is in for a world of hurt. But the blame will have to be shared by an inert Democratic electorate and the passive Obama Administration which caused it.
In other words - Barack, people are more willing to fight for someone who is fighting hard himself.
In still more other words - Get your ass out of the White House and get fired up. Or you will only have yourself to blame.