From one of my Wall Street Guys:
I was wondering just this last night. A few points. First, the glory days of economic growth came in the late 90s, when we had split government, with neither party controlling the executive and the legislature, so vetoes were a real barrier to dramatic legislation. I do not think the prospect of a Democratic win in either or both houses is driving the market, but I think it is safe to say that it is not troubling the market. Moreover, thoughts that the Fed might cut rates next year makes the equity markets very happy.