Pennsylvania's Supreme Court justices are hearing arguments over whether a new law requiring each voter to show valid photo identification poses an unnecessary threat to the right to vote.
The high court session began Thursday, 54 days before Pennsylvanians help decide who will be president.
The state's lawyers say lawmakers properly exercised their constitutional latitude to make election-related laws and that every registered voter, including those suing, will be able to cast a ballot.
But lawyers for the plaintiffs insist many registered voters don't know about the requirement, don't have a valid ID or will be unable to get one.
The high court is hearing the politically charged case with just six justices: three Democrats and three Republicans. A 3-3 deadlock would allow the law to stand.