A little over a year after Colorado and Washington legalized marijuana, more than half the states, including some in the conservative South, are considering decriminalizing the drug or legalizing it for medical or recreational use. That has set up a watershed year in the battle over whether marijuana should be as acceptable as alcohol.

Demonstrating how marijuana is no longer a strictly partisan issue, the two states considered likeliest this year to follow Colorado and Washington in outright legalization of the drug are Oregon, dominated by liberal Democrats, and Alaska, where libertarian Republicans hold sway.

Advocates of more lenient marijuana laws say they intend to maintain the momentum from their successes, heartened by national and statewide polls showing greater public acceptance of legalizing marijuana; President Barack Obama’s recent musings on the discriminatory effect of marijuana prosecutions; and the release of guidelines by his Treasury Department intended to make it easier for banks to do business with legal marijuana businesses.

Their opponents, though, who also see this as a crucial year, are just as keen to slow the legalization drives. They are aided by a wait-and-see attitude among many governors and legislators, who seem wary of pushing ahead too quickly without seeing how the rollout of legal marijuana works in Colorado and Washington.

"We feel that if Oregon or Alaska could be stopped, it would disrupt the whole narrative these groups have that legalization is inevitable," said Kevin A. Sabet, executive director of Smart Approaches to Marijuana, which is spearheading much of the effort to stop these initiatives. "We could stop that momentum."

Despite the drug still being illegal under federal law, the Obama administration has said it will not interfere with the rollout of legal marijuana in the states, as long as it is kept out of the hands of minors.

At least 14 states — including Florida, where an initiative has already qualified for the ballot — are considering new medical marijuana laws this year, according to the Marijuana Policy Project, which supports legalization, and 12 states and the District of Columbia are contemplating decriminalization, in which the drug remains illegal, but the penalties are softened or reduced to fines. Medical marijuana use is already legal in 20 states and the District of Columbia.

An even larger number of states, at least 17, have seen bills introduced or initiatives begun to legalize the drug for adult use along the lines of alcohol, the same approach used in Colorado and Washington, but most of those efforts are considered unlikely of success this year.

The allure of tax revenues is also becoming a powerful selling point in some states, particularly after Gov. John W. Hickenlooper of Colorado said last week that taxes from legal marijuana sales would be $134 million in the coming fiscal year, much higher than had been predicted when the measure was passed in 2012.

In Rhode Island, which is struggling financially, national and local advocates for legalization say the Colorado news is sure to help legislation introduced in February to legalize the drug.

"Some feel it’s not an appropriate issue for an election year, and others want to wait and see what happens in Colorado," said state Sen. Joshua Miller, a Democrat who is sponsoring the Rhode Island legalization law. "But a lot of other people are very anxious to take the revenue part of this very seriously."

Opponents of legalization, meanwhile, are mobilizing across the country to slow the momentum, keeping a sharp eye on Colorado for any problems in the rollout of the new law there.

"Legalization almost had to happen in order for people to wake up and realize they don’t want it," Sabet said. "In a strange way, we feel legalization in a few states could be a blessing."

California had been considered a possibility to legalize marijuana this year through a ballot proposition — one to do just that failed in 2010 — but the Drug Policy Alliance, which had been leading the effort, decided this month to wait until 2016.

While much of the recent attention has focused on these legalization efforts, medical marijuana may also cross what its backers consider an important threshold this year – most notably in the South where Alabama, Georgia and South Carolina are among the states considering such laws.

John Morgan, an Orlando lawyer whose firm includes former Gov. Charlie Crist, has spent $3.6 million of his own money to get a medical marijuana initiative on the November ballot in Florida, where partisan polling has shown strong support but state law requires 60 percent to pass.

Morgan insists that his initiative is not intended to help Crist, a Republican turned Democrat, reclaim the governorship.

Election data, complied by Just Say Now, a pro-marijuana group, showed that the percentage of the vote that came from people under 30 increased significantly from 2008 to 2012 in states that had marijuana initiatives. This youth vote, predominantly Democratic, rose to 20 percent from 14 percent in Colorado, and to 22 percent from 10 percent in Washington, both far above the 1 percent rise in the national youth vote.

"If it benefits Charlie Crist, it’s certainly an unintended consequence," Morgan said.

Sabet said his conversations with Democratic leaders around the country convince him that there is little enthusiasm for being high-profile on the issue. "For the moment, I think by and large, Democrats are uncomfortable with that," Sabet said.

In Maryland, though, the marijuana issue is already playing a role in the governor’s race, where all three leading Democratic candidates are talking about how much and how fast to ease marijuana laws, not whether to do it at all.

A narrow majority of Americans — 51 percent — believe marijuana should be legal, according to a /CBS News poll conducted last week, matching the result in a CBS News poll the previous month. In 1979, when The Times and CBS first asked the question, only 27 percent wanted cannabis legalized.

There were stark differences in the new poll, though. While 72 percent of people under 30 favored legalization, only 29 percent of those over 65 agreed. And while about a third of Republicans now favored legalization, this was far below the 60 percent of Democrats and 54 percent of independents who did so.

In Alaska, sufficient signatures have been collected to get the legalization initiative on the ballot.

"Alaska is a red state, but with a heavy libertarian streak," said Taylor Bickford, spokesman for the Campaign to Regulate Marijuana Like Alcohol in Alaska. "The idea of personal freedom and responsibility is uniting Alaskans on both sides of the aisle."

Under state law, however, the vote will occur during the Aug. 19 primary, not in the general election.

"The support in Alaska is very strong, but how do you poll on an issue like this for a low-turnout primary election?" asked Ethan Nadelmann, executive director of the Drug Policy Alliance. That is why he thinks Oregon really has the better chance this year.

Anthony Johnson, the director of New Approach Oregon, a coalition that is leading the drive there, said advocates are trying to persuade state legislators to put the issue on the November ballot while simultaneously preparing to collect the roughly 88,000 signatures that would be needed to force it onto the ballot if the legislators demur.

"At the moment, I’d say the odds are no better than 50 percent that the Legislature will act," Johnson said. "But if they don’t, we will just gather the signatures. I am pretty confident we will be able to get them."

Mason Tvert, director of communications for the Marijuana Policy Project, a leading advocate for legalizing marijuana, said campaigns were already underway to stage aggressive legalization drives in several states over the next couple of years, including Arizona, California, Maine, Massachusetts, Nevada, and possibly Montana.

"It is certainly important to maintain the momentum," Tvert said, "But I don’t think we can look at any one election cycle and see what the future holds. This is going to be a multiyear effort."

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