The war on terrorism has changed the political landscape dramatically and the Bush administration is faced with serious problems no President and no other American generation, has ever come up against before.
Bushes record hasn't been perfect in the last year. He's made some wrongheaded moves involving a few key pieces of legislation, but were its been possible, the President has moved his agenda along. Working to take back the Senate should be the priority for every conservative Republican. Having a Democrat controlled Congress, will only exascerbate the political gridlock that exists in WashDC today.
If we can only have one chamber, I'd almost trade the House for the Senate. With the power divided, we still get bigger government. With the Senate in republican hands, Bush can at least affect the composition of the judiciary (which in any case has become a "secondary legislature").