Over the past five or ten years, Democratic politicians have all but completed a full evolution (to use President Obama's term) on the subject of gay marriage. In 2008, both Hillary Clinton and Obama were against gay marriage. In the 2012 election, Obama came out in support while Hillary did so about a nanosecond after she stepped down as Secretary of State. It is now getting tougher and tougher for any Democratic politician to not support gay marriage. As I said, the evolution is almost complete within the party. The question I now ask is how long that evolution is going to take on a different subject: marijuana reform.

The reason the question is in the news is that Maryland's governor, Martin O'Malley, just signed a law which decriminalizes marijuana in his state. This is interesting for a number of reasons, not least of which is that it is no secret that O'Malley sees himself as future presidential material and he'll soon be running hard (for at least Hillary's veep slot in 2016) to achieve this goal. What is more interesting is that O'Malley initially didn't support the bill, and in fact spoke out against it as it was being debated. But now he has signed it, because his own party in the legislature disagreed with O'Malley. It remains to be seen whether he'll actually become a champion of the law or not, but he sure sounds pretty positive about it so far.

Marijuana laws are fast being seen by majorities of the public as hopelessly outdated and downright Draconian. Of course, this varies from state to state and region to region, but on some questions overwhelming majorities are in agreement that it is time to change the laws. The people are leading, and the leaders are finally following, although slowly. The new Maryland law isn't all that radical -- many states have much more lenient laws -- but the real news is that the old laws are now the ones seen as "radical" (in the other direction) by the public. This is evolution.

The path this evolution is taking is three-fold, really. In the "Just Say No" Nancy Reagan era of the War on Drugs, politicians were falling all over themselves to prove how "tough on crime" they were. Some astoundingly bad laws got passed, and many are still on the books. This, in other words, was the starting point for the political pendulum to now swing back in the other direction. The three steps of this path happen when a big majority of the public agrees with the following notions:

• Handing out long jail sentences and other heavy punishments for smoking pot is a waste of money, time, and lives.
• People who use marijuana medicinally should be allowed to do so without fearing arrest.
• Marijuana should be regulated and taxed like alcohol and tobacco.

The American public overwhelmingly agrees with the first two of those. The numbers aren't even close. Marijuana possession should be treated -- at worst -- like a traffic ticket, and not as some sort of serious crime. Now, of course, every state hasn't changed their laws to decriminalize marijuana yet, but more and more states are now in the process of doing so (Maryland was just the most recent example, in other words). Medical marijuana is now supported in public opinion polls by over 70 percent of the people. Even though less than half the states have so far legalized medical marijuana.

Of course, the last item on that list is only true -- so far -- in Colorado and Washington states. The larger American public is slowly coming around to supporting this view, but so far the numbers are only (roughly) even on the question. As tangible results of the Colorado/Washington experiment start showing up (crime is already down in Colorado, for instance), the public at large is going to become more and more open to the "tax and regulate" stance, though. This evolution is not complete, to put it another way, but it is continuing steadily -- in one direction.

Democratic politicians now have two basic choices: deny this trend in the public's attitudes, or get out in front of it. O'Malley kind of did both at once, although one hopes that he truly has evolved and will now stick with his newfound support. His case is especially interesting, because his ambitions for the White House are so apparent to all. Meaning he could define the field on the issue, since he's the only one so far in the running. Other Democratic hopefuls -- including Hillary, of course -- will have to face the issue as well.

The real driving factor behind the Democrats is an interesting result from the election which legalized recreational marijuana in Colorado. In 2012, when the referendum was on the ballot, it got more votes than President Obama did. Several percent higher, in fact. This signifies that there is a segment of the population out there for whom it is a crossover issue. If Obama had come out in full support of Colorado's referendum issue, he might have picked up three or four percent in the state. Now, this wouldn't have really mattered, since Obama won Colorado anyway. But picking up three or four percent would have meant the difference for Obama in winning North Carolina in 2012, and both Missouri and Montana in 2008.

More to the point, Democratic candidates for office are going to find themselves increasingly out of step with their own base voters on the marijuana issue, unless they begin evolving. In the next few elections, most Democrats will likely try to weasel their way out of taking a strong stand on the issue in either direction. There was a similar period of Democratic weaseling on gay marriage, which began in the 1990s and didn't really end until 2012.

The people have evolved, at least on the question of decriminalization and medical marijuana. They have firmly moved their opinion, and this trend is simply not going to reverse any time soon. The people are now moving on the question of open legalization, and this trend is just as easy to see. Some Democratic politicians have realized this, and are getting out in front of it -- most notably Gavin Newsom in California (who will likely run for governor after Jerry Brown's fourth term). Newsom has already expressed support for the push to get recreational marijuana onto the ballot in 2016. He was also a very early supporter of gay marriage, you'll recall, marrying people on the steps of San Francisco City Hall. At the time, many Democrats thought Newsom was crazy and taking a huge political risk. They would have preferred to keep weaseling on the issue.

My prediction is that by 2016, Democrats on the national stage will be forced to at least take a clear stance on marijuana law. Perhaps not every one of them will fully support all reform efforts, but they will at least be forced to talk about it and explain their position to the public. More and more states are legalizing forms of medicinal marijuana, but the federal government is still treating marijuana as legally more serious than methamphetamine. While individual states can certainly keep advancing marijuana legal reform, action is needed on the federal level. Democratic politicians are going to need to start examining their own position on the issue, because it is only going to get bigger and bigger on the national stage. They're going to need to evolve, in other words -- and soon.

-- Chris Weigant

Follow Chris on Twitter: @ChrisWeigant