Republicans approve of a Democratic controlled Congress significantly more than do either Democrats or Independents. Really, it makes sense, since the conservative governing majority in Washington has not been stopped by Democratic control of Congress. FISA was passed into law. The Iraq war has escalated, without any conditions being attached to it. Liberal political speech is condemned on the floor of the Senate. Republican filibusters are at a record high blocking everything in sight, and when that fails there is still Bush's veto to whip Congress into line. Effectively, Washington is still governing to the benefit of Republicans, and to the disgust of Democrats and Independents.
You know, I have to admit, that outside of the residual forces disaster, Hillary Clinton is rapidly moving up in my rankings of Democratic candidates for President. Say whatever else you want about the Clintons, but they don't take bullshit Republican attacks lying down or cowering in a corner. And if there is one thing I can't stand right now it is Democrats who won't stand up for themselves, who stab their allies in the back in order to appeal to D.C. elites and Republicans, and then ask us to keep fighting for them. At least Clinton fights back, and hard, whenever attacks are directed her way. That is a big plus in my book.