The state has made a series of improvements — some voluntary and some mandated by the court — to ensure most voters seeking an ID can obtain one, he said.

"We are trying very hard to correct any errors," Tseytlin said.

But Crawford argued the state's program, as it stands, is unsustainable.

The problem with Wisconsin's voter ID law, she said, is that it lacks a sufficient safety net.

Wisconsin voters who show up to the polls without the proper ID can cast a provisional ballot, which will be counted if the voter can show a qualifying ID within three days. Crawford, who has represented the League of Women Voters in ongoing litigation against the law, contrasted that with other states that offer the ability for those voters to sign an affidavit swearing to their identity.

"To me, it would be acceptable if we had a voter ID law in this state that had an affidavit process built into it," Crawford said, adding there are still additional improvements to the law that she would suggest.

McDonell also argued in support of allowing an affidavit process. As an elections administrator, one of the biggest challenges McDonell said he has with the voter ID law is its ability to slow down lines at polling places.