Rolling Stone has an article detailing how:
From New Hampshire to California, officials have designed complex questionnaires that prevent college students from registering, hired high-powered attorneys to keep them off the rolls, shut down polling places on campuses and even threatened to arrest and imprison young voters. Much as local registrars in the South once used poll taxes and literacy tests to deny the vote to black citizens, some county election officials now employ an intimidating mix of legal bullying and added paperwork to prevent civic-minded young people from casting ballots.
This also presents problems for national and state votes, since it means they would have to travel “home” in order to vote. With a system like this intended to disenfranchise a large group of voters who are usually very vocal, it flies in the face of anyone who claims that the younger generation is apathetic towards politics.