 The SAVE Act requires anyone registering to vote in a federal election to be able to prove that they're U.S. citizens. That simple. Now, it's already against federal law for a non-citizen to vote in a federal election. But oddly enough, there are a series of laws already in place that, when read together, make it very easy for people to go and get a driver's license. And in the process of getting a driver's license, all they have to do is check a box and sign their name to something.