NEW YORK (MainStreet) — The Senate Appropriations Committee passed an appropriations bill that did not include the prohibition against marijuana enforcement that the House appropriations bill did. Legalization opponents were elated but advocates are working to include this provision when the bill goes to a full Senate vote.

On May 30, the House enacted the passage of an amendment to the Department of Justice (DOJ) appropriations bill. This amendment prohibits "the use of funds to prevent certain states from implementing their own State laws that authorize the use, distribution, possession, or cultivation of medical marijuana."

The amendment (no. 748 to House bill H.R. 4660) was passed by a coalition of 49 Republicans and 170 Democrats. It was deemed historic at the time, because it represented a seismic shift in the attitude within the House of Representatives toward marijuana legalization.

What was encouraging to marijuana legalization advocates was the conservative Republicans who voted for the bill. Indeed, the sponsors included Republicans who were considered conservative and liberal Democrats. People like Tom McClintock ( R-Calif.) and Dana Rohrabacher (R-Calif.) joined with ultra-liberal Barbara Lee (D-Calif.).

This Republican embrace of marijuana legalization is not so much conservative as it is libertarian - said Republican operatives. This is an indication that libertarianism is becoming entrenched in Republican Party politics. Libertarians have been calling for legalization of all controlled substances - from heroin to marijuana and everything in between.

"This is historic, a victory for states' rights, for the doctor-patient relationship, for compassion, for fiscal responsibility," Rohrabacher said.

But while politicians like Rohrabacher claim to be for the doctor-patient relationship, the medical community opposes medical marijuana. The American Medical Association, the largest physician association in the United States, reaffirmed its stance against marijuana legalization last November.

The American Academy of Pediatrics and the American Society for Addiction Medicine oppose legalization of marijuana pending more research.

Even the American Psychiatric Association expressed disapproval in December 2013.

"There is no current scientific evidence that marijuana is in any way beneficial for the treatment of any psychiatric disorder," it said. "In contrast, current evidence supports, at minimum, a strong association of cannabis use with the onset of psychiatric disorders. Adolescents are particularly vulnerable to harm, given the effects of cannabis on neurological development."

But despite the opposition of the medical community, advocates want medical marijuana legalized both at the state and federal level. Politicians in the House have introduced this enforcement prohibition for years. This is the first time it passed.

Right now they are not sounding the alarms about the Senate committee action.

Chris Hermes, a spokesperson for Americans for Safe Access a group advocating marijuana use, said they are in the process of getting this provision in the Senate bill. It is not the Senate is not interested.

"We did not have a committee sponsor for a Senate version of the House amendment," said Hermes. "We are looking to find someone to attach an amendment when the bill goes to a floor vote in the full Senate."

"What we and the co-sponsors (of the House amendment) are trying to do is figure out what the best approach will be vis a vis the Senate," explained Ken Grubbs, spokesman for Rep. Rohrabacher.

But there is no guarantee such an amendment would pass since one of the leading opponents of a provision to defund enforcement efforts is Sen. Dianne Feinstein (D-Calif.). The powerful senator is a staunch opponent of marijuana legalization. She is the chair of the Senate's Caucus on International Narcotics Control, which oversees U.S. counternarcotics policy. The caucus works to "combat international narcotics trafficking and reduce domestic drug abuse."

Feinstein's opposition is in sharp contrast to the "conservative Republican," her fellow Californian Rohrabacher. But it is an issue that cuts across party lines.

A number of other senators on both sides of the aisle have expressed their opposition to marijuana decriminalization.

--Written by Michael P. Tremoglie for MainStreet