It should definitely be compulsory. We are lucky enough to live in a country where we have the right to vote for whomever we choose, and not exercising that democratic right is such a shame. I'm pretty sure something like just over 50% of Americans partake in voting... Which means half of America hasn't had a say in who they want to lead their country. Politics is something that affects everyone, I don't understand why anyone wouldn't want to be involved in such an important decision.
I do think there needs to be more education on how our government works, the different parties, etc so people are making more informed decisions when they vote.