1. Stand your ground.
A friend of mine in North Carolina was almost disenfranchised at her early voting station. She refused to move until they let her vote. Strangely enough, they eventually did let her vote.
If you are registered to vote, you are at the correct polling station, and there is no other good reason why you should not vote, DO NOT LEAVE UNTIL THEY LET YOU VOTE. State your case to officials clearly and civilly. Ask to speak to a supervisor. Explain that you are registered, show your state ID and voter registration card, and ask why they will not let you vote. Ask poll workers to call county officials, if necessary. Be polite and respectful at all times.
If they still will not let you vote,
2. Contact local elections officials.
Again, be polite. Ask what the problem is, and work with them to solve it, if possible. Have documents ready to prove your residence in the correct state and county. Your state ID and voter registration card should be of help here. Copies of tax forms are an excellent proof of residence. You pay taxes - your vote should be heard!
If you are still not allowed to vote,
3. Contact national groups for citizens’ rights.
Such groups as the ACLU were created specifically to protect citizens. In such a confused election year, they will have had quite a few complaints and questions about the voting process. You are of great importance to them! Tell them your story, and they will take appropriate legal action to ensure your say in a democratic government.
The ACLU has started a voter protection effort here:
http://www.aclu.org/VotingRights/VotingRightsMain.cfm
Their hotline number is 1-877-523-2792.
Moveon.org has a set of instructions on their “What do do if you’re disenfranchised” card, which is here:
http://cdn.moveonpac.org/content/pdfs/ep_card.pdf
Their hotline number is 1-866-MYVOTE1.
Caveat: I am not a lawyer. I am just suggesting actions that make legal sense to me. I do think, however, that this election is, and its outcome will be, EXTREMELY IMPORTANT in the outcome of world affairs for the next four years. We cannot afford to have a single citizen disenfranchised. Please vote.
Transitional Man says: According to my mom, who used to be a regional co-ordinator for the Ohio Secretary of State, insist on voting. They will seal a ballot with eligibility to be determined later. Don't leave without voting.
wonko6942 says: What Transitional Man was talking about are "provisional ballots", and are part of the Help America Vote Act -- they'll cover most "left out" voters EXCEPT those in the wrong precinct.
gitm says: Colorado also has provisional ballots thanks largely to enormous registration fraud here. People can fill out a provisional ballot and their eligibility will be researched by the election commission.