The Legislative Branch unit usually falls somewhere before Thanksgiving which is a perfect time to assign this cute little hand turkey project describing how a bill becomes a law.
On the day before Thanksgiving break, set up a Turkey Bowl: Constitution edition and challenge fellow American Government teachers to a friendly (but in reality an ugly and competitive) epic battle of wits. I normally have everyone meet in the auditorium during lunch for the trivia game. Or, if you don't have space to fit all the students, you can use Google hangouts to video conference your colleagues from your classroom. There's also the option of a Jeopardy Style review game if none of this falls around Thanksgiving.