Does voting violate the Non-Aggression Principle (NAP)?

Short answer: No, if you are voting defensively rather than aggressively.

Longer answer: If the reason you are voting is to gain benefits at the expense of someone else, e.g., subsidies from the State, then it violates the NAP. However, if the reason you are voting is to try to defend yourself against aggression in the form of higher taxes, more regulations, or other State intrusions in your life, then it does not violate the NAP.

Furthermore, defensive voting not only does not violate the NAP, but it doesn’t violate the Golden Rule either, as everyone has (and should have) the right of self-defense.