The Minnesota Senate has overwhelmingly backed the legalization of medical marijuana, voting 48-18 with a strong bipartisan majority that would be enough to override a veto by Gov. Mark Dayton. 

A House vote on a more limited medical marijuana proposal could come as early as Friday. 

There are significant differences between the two proposals. The more expansive Senate version would allow marijuana to be grown and dispensed at up to 55 sites around the state.

"For God’s sake, if people are suffering and we have the ability to provide a way to alleviate the pain, let’s hear their concern, let’s hear their prayer,” said Sen. Charles Wiger, DFL-Maplewood. 

The more limited House version would authorize only one grow and dispense site under strict supervision by the state Department of Health.

The Senate proposal also puts looser limits on what kind of patients would be eligible for medical marijuana. Among those who could get a doctor's permission to obtain a medical marijuana license are patients suffering from cancer, HIV/AIDS, glaucoma, Tourette's syndrom, ALS, seizures brought on by epilepsy, muscle spasms caused by multiple sclerosis, Crohn's disease, post-traumatic stress disorder and a handful of conditions that cause chronic pain. Those last two conditions are not included in the House proposal.

Neither the House nor Senate bills allows patients to smoke marijuana. Both allow the drug to be consumed with the aid of a vaporizer, which heats the drug without actually combusting it. Patients could also access it in pill or oil form. 

The House proposal has been tailored to neutralize objections from law enforcement groups, who are opposed to the Senate bill and whose support is likely to be the chief factor in whether Gov. Mark Dayton would sign a bill to legalize medical marijuana. 

But the House's more modest approach has disappointed many medical marijuana backers, who say its approach of state-backed research into medical marijuana over wider patient access has proved unworkable in other states. 

"I wish we could do something more expansive," said Rep. Tim Mahoney, DFL-St. Paul, in the Ways and Means hearing. The committee approved the proposal and sent it to the House floor, with a debate likely on Friday. 

With significantly different medical marijuana bills likely to come out of the House and Senate, a conference committee would be called to produce a final version of the proposal.