Should the Republicans get a majority in one or both houses of Congress, how will the President react?  My guess is that he won't be in an accommodating mood.  President Obama seems to be the kind of liberal who thinks that his analysis of things is the simple truth.  Others may come to different conclusions, but that's only because they have not thought hard enough about things, or, perhaps, they have narrow, or interested motives. In short, they are political; he is not.  Obama sees his ideas as being above politics; those who disagree with him are being political, and dividing us.  By contrast, his ideas are designed to unite us.  If that analysis is correct, he will dig in against a majority that disagrees.

One further point on the same subject.  President will probably also think he can imitate President Clinton, and get the GOP Congress to overplay its hand.  He may be able to do that.  On the other hand, after 1994, the main elements of the Clinton program were welfare reform, school uniforms, stable money, deficit reduction, a capital gains tax cut, and war in Bosnia.  I don't think Obama can pivot like that.  President Clinton refused to sign a budget and was able to blame the Republicans for shutting down the government only because he had moved in a centrist direction.  During the 2008 campaign, President Obama convinced many he was a centrist.  It will be harder sell now.