Democrats seem unable now to pass much relevant legislation, I doubt Republicans would do much more. Stalemate. I'm aware of a gun control kind of bill that could pass the Senate, maybe, the details are being haggled now. I really don't know what a Republican Congress could get passed and signed that would matter much to the economy.
If we hit a full bore recession, I could see more "stimulus bills" being passed no matter who is in control. Deficit spending, yay.