(RALEIGH) -- Lawmakers are considering a measure that would require photo identification in order to vote.

Opponents say that would amount to an illegal poll tax. Supporters say voters could obtain free voter identification cards affixed with photos through county election boards if they don't have another valid ID.

Former NC Justice Bob Orr is Executive Director and Senior Counsel for the NC Institute for Constitutional Law. Orr says lawmakers must be careful in asking voters for additional requirements in order to cast a ballot.

Orr suggested that a photo ID to prove registration might be permissable.