Obama has been overruling Congress anyway. If we elect conservatives to Congress, he will just go over them. There is no chance Obama would ever go along with a conservative Congress. Especially since He can’t be re-elected. With Romney, we at least have the chance to have someone that will go along with a conservative Congress.
You've got it backwards. A 'conservative' Congress will roll over for the guy in the White House because he's the boss of their party.
On the other hand, that same Congress would fight the other side's boss tooth and nail.
Art of War 101.