Arizona veterans are pushing back against a university ban on medical marijuana, which was legalized by voters seven years ago.

A petition on backed by a veterans group warns that the University of Arizona Police Department will "lock up" medical marijuana users.

"People truly don't understand us. They don't understand why we don't want pills," said Dan Schmink, an Army veteran of Iraq.

His business, Southwest Healing Group, helps other veterans adapt to life after the military. For many, he said, medical marijuana is a lifeline.

"Why should a university, which is supposed to be the progressive center of tomorrow, say 'No'? It doesn't make sense to me," Schmink said.

Arizona voters legalized medical marijuana in 2010. But two years later, the State Legislature banned medical marijuana on university campuses. Possession there is a felony.

Marijuana is still illegal under federal law. Universities are concerned they could jeopardize federal funding by ignoring that law.

"I do know there are veterans that rely on cannabis every single day to get through their classes so they can get that degree," Schmink said.

There is a chance the courts will throw out the campus ban on medical marijuana.

An ASU student who is a medical marijuana cardholder was convicted of possessing marijuana in 2015.

He has appealed the verdict as unconstitutional, because of the 2010 vote that legalized medical marijuana.

A University of Arizona official said the campus ban was based on state law. A university poster on campus, however, cites federal regulations for the medical marijuana ban.

Arizona State University's Police Department issued this statement:

Marijuana on campus is prohibited by state law and by federal laws. Students who commit violations of the Student Code of Conduct that involve marijuana are guided to substance abuse resources. They may be subject to disciplinary action, ranging from probation to expulsion.