After a debate pitting compassion for those suffering from the pain of cancer or HIV-AIDS against concerns about abuse and violence from expanded availability of a "gateway drug," the Minnesota Senate gave tentative approval Wednesday to the use of marijuana for medical purposes in the state.

The 36-28 vote came despite questions about whether the measure fully defines who would be eligible and whether it provides proper safeguards against potential abuse.

Law enforcement has consistently opposed medical marijuana, but Sen. Steve Murphy, DFL-Red Wing, chief author of the bill (S.F. 97), said during debate that the measure is a medical issue, not one for "our brothers and sisters in blue."

The Senate has approved medical marijuana legislation in the past, but it has always stalled in the House. Advocates believe they have enough votes to pass it there this year, but it seems less likely they have enough to override any possible veto from Gov. Tim Pawlenty, who has expressed reservations about the bill. The bill could be heard on the House floor next week.

"I'm here to tell you there is potential opportunity for abuse here, and kids are watching to see what we in the Legislature are going to do," said Sen. Bill Ingebrigtsen, R-Alexandria, a former county sheriff.

Sen. Julianne Ortman, R-Chanhassen, said she was concerned that the supply of marijuana will lead to theft and violence. "Sections of Minnesota with storefronts in big cities and small cities will have signs that say marijuana is accessible and for sale," she said.

Thirteen states have passed medical marijuana laws. The Senate's vote was preliminary but is a good barometer of the outcome of an official vote, which is likely to come today.