PHILADELPHIA, Penn. (CBS) -- Pennsylvania's Supreme Court heard arguments today both for and against the state's controversial new voter identification law. It requires voters to show photo ID before casting a ballot.

Demonstrators gathered outside a Pennsylvania state Supreme Court hearing to protest the new voter id law. They say it unfairly targets the elderly, poor and minorities. Ben Jealous with the NAACP says, "What we are fighting for in this moment is democracy itself. Our opponent thinks this will tilt things in their favor."

Inside lawyers for the plaintiffs argued the new law will keep a large number of registered voters from casting a ballot. The plaintiff's attorney David Gersch says, "There's too little time, there's too many people affected, and there is no place in the statute that guarantees qualified electors, can get the ID they need to vote."

A lower court judge upheld the law last month which requires voters to present a valid photo id at the polls. The state says the law protects against voter fraud. Pennsylvania Chief Deputy Attorney General John Knorr says, "It's simply a means to establish that you are who you say you are and are therefore a registered voter."

Since 2011, nine other states have passed similar laws. In Pennsylvania, some estimate at least 100,000 registered voters still do not have a valid ID.

With time running out to get one before the presidential election, one justice questioned whether the state should wait to implement the law. Justice Seamus McCaffery says, "My question is What's the rush?"

The court is expected to issue a ruling before the end of the month. The court normally has seven members but only six justices listened to the arguments; three democrats and three republicans. If they deadlock, the law will stand.