With your prior knowledge government institutions and domestic policy shouldn’t be difficult for you. But a good portion of the exam does test on politics. Just read the REA Crash Course book, I believe it was written by the author who wrote Direct Hits and 300 Essential SAT words so it is a very good book. One thing that is always on the exam is what age group votes the most and that is old people. Apart from that do old FRQs and practice tests. Good luck!</p>