As legislatures nationwide debate whether to legalize medical marijuana, colleges and universities in states where laws have been adopted say their campuses will remain drug-free.

The reason: Marijuana use and possession violates federal law, and colleges don't want to risk losing federal funding.

This year, 13 state legislatures are considering proposals to legalize medical marijuana, and four more are looking at bills, says Morgan Fox of the Marijuana Policy Project, a group that advocates loosening marijuana laws. Proposals to tighten or ease laws are pending in at least 10 of the 15 states, plus the District of Columbia, where medical marijuana is legal.

Colleges say they have no choice but to abide by the federal rules and keep marijuana off their campuses