"What can I do, besides vote, to exercise my rights as a citizen?"

The person behind me in line at the doctor's office asked this out of the blue. And I had an answer ready: "Pay attention to your local politics. Attend city council meetings, write to your representatives."  It doesn't matter what your political leanings are, but you should be involved in your home town government. Whether you agree or disagree with national policies, your local government is where those policies will affect you. Your local authorities will be where you interact with the law - get to know them. Attend 'coffee with a cop' events. Get to know your community."

Since that short conversation, I've thought of additional things that anyone can do to make a difference to America: If you are a resident alien, consider applying for citizenship.  If you are a citizen, encourage others to become citizens as well.

And, yes, vote. Encourage and help others to do so as well. According to reports a large percentage of registered voters don't bother voting. Can you do something to change that? Find out.