I don't incorporate much politics into my economic forecasts. I'm no better than average at predicting electoral outcomes. Even if I knew who was going to win, I wouldn't know what that person would do as president. (I didn't expect Bush II to push for steel tariffs or a Medicare drug benefit; I didn't expect Obama to maintain war in the Middle East or domestic surveillance without warrants.) And finally, even if I knew who would win and what that president would try to do, I wouldn't know that Congress would go along.
That said, I try to keep my ear to the ground. The best way I've found is Larry Sabato's Crystal Ball. I got a lot out of his 10 Factors That Will Determine the Next President.