Reply #8: It's a violation of the Equal Protection Clause of the Fourteenth Amendment.

[Jim Lane]

In , a 1966 decision, the Supreme Court held that "a state violates the Equal Protection Clause of the Fourteenth Amendment to the U.S. Constitution whenever it makes the affluence of the voter or payment of any fee an electoral standard." If the state requires the voter to show a state-issued identification but charges a fee for any such document, then it's requiring "payment of any fee" as a condition for voting.

If the state were to issue an ID without charge, it would still depress turnout, but there would be a better case for its legality.