The American Civil Liberties Union sued Alabama elections officials Monday over what it says is an overly expansive policy disenfranchising felons, amid concern from voting rights groups nationwide that voting lists are being culled with too great alacrity by many states.

Like virtually all states, Alabama restricts the rights of many felons to vote, but in Monday’s suit the group contends the state is going beyond even its own laws. People convicted of nonviolent offenses like income tax evasion or forgery are at risk of being turned away by voter registrars in Alabama, the A.C.L.U. says.

Alabama does not bar all felons from voting, only those convicted of crimes involving “moral turpitude.” In 2003, the civil liberties group says, the State Legislature clearly defined what those crimes are: murder, rape, sodomy, sexual abuse, incest, sexual torture and nine other crimes mainly involving pornography and abuses against children.

At issue in the lawsuit is not the list enacted in law but an expanded “moral turpitude” list developed by the state’s attorney general, Troy King, in 2005. That list includes about a dozen additional offenses, most of them nonviolent, and several including the sale of marijuana.