The Amish are free to vote, but very few do.This is because the Amish do not want to be conformed with the world and many regard voting as conforming with the world.
"The church forbids membership in political organizations and holding public office for several reasons. First, running for office is viewed as arrogant and out of character with esteemed Amish values of humility and modesty. Second, office-holding violates the religious principle of separation from the world. Finally, public officials must be prepared to use legal force if necessary to settle civic disputes. The exercise of legal force mocks the stance of nonresistance. Voting, however, is viewed as a personal matter. Although the church does not prohibit it, few persons vote. Those who do vote are likely to be younger businessmen concerned about local issues. Although voting is considered a personal matter, jury duty is not allowed."