Because the Republican leadership is still in denial, and do not want to learn from their mistakes. The short era of bipartisanship is over. Republican Senators, especially those from the south. are not going to go along with the new era of bipartisanship.
Last week, we learned that GOP Senators are setting up a first fight with the Obama administration over the Eric Holder nomination. Now, we find out, via Think Progress, that the Republican Senators have Karl Rove leading their strategy: