The first 2 lessons lessons are #1 Your principles and ideals are irrelevant unless you can get sworn in, that isn't what "Politics" is about. It's entirely about getting, and using power regardless of your goals. The Democrats get this and do it well. The Republicans don't, therefore they have to depend on the voters becoming disgusted with the Dems.
#2, Study Saul Alinsky and Machiavelli's " The Prince".