Thomas Sowell gets to it in his column today:

Congressional Republicans don’t have enough votes to stop any legislation or confirm any judges, especially since the Democrats stick together, unlike Republicans. Moreover, with a Republican president saying that he wants both a bipartisan immigration bill and a bipartisan minimum-wage bill, there is not even a hope of a veto.
But the fact that you cannot stop something does not mean that you have to become an accomplice. There is no reason why a majority of Republican senators should ever again vote to confirm another extreme activist judge like Ruth Bader Ginsburg. Nor is there any reason why congressional Republicans should again outrage their supporters by voting for another illegal-immigration amnesty bill. Not unless they want to be chumps again in 2008.
… Congressional Republicans will have to face the voters again in 2008, even if President Bush does not.