Both parties chose to run against people who were not even on the ballot yesterday. Republicans ran against the President and largely won. Democrats ran against the Koch brothers (who are not even elected officials or even the largest private donors in the election) and to a lesser extent against mythical candidates who were going to ban all contraception, and lost.
Honestly, I can only remember three elections in the last 40 years with changes in power that really mattered in terms of actual legislative and policy changes: The first term Reagan and Obama elections and the midterm election of the Gingrich Republicans in '94.
This Republican class lacks the unity around a written legislative agenda that the Gingrich Republicans had. So I don't really expect much. The best we can hope for is perhaps a bit more effective push-back against creeping executive power, which certainly would be welcome.