In Politico, Reid Cherlin has an article about the "Pot Primary" in which he makes the rather odd assertion that while the next Democratic president is likely to put him/herself where President Obama is on the issue, "Less predictable is what would happen under a Republican—or how the issue might play out in a volatile Republican primary. No one expects marijuana to be the deciding issue, but then again, it might well be a helpful way for the contenders to highlight their differences."
Yeah, no. Apart from the possibility of some talk about not sentencing people to overly long prison terms for possession, there isn't going to be a debate amongst 2016 GOP candidates on this issue. The debate will all be on the Democratic side.
The reason is that as much as Republicans would like to appeal to a younger, more diverse electorate, in the general election the candidates will be working to win the hearts of activist Republican voters. That means an electorate that is older, whiter, more rural, and more religiously conservative than America as a whole. These are not your pro-pot voters. As a CNN pollster said about their most recent survey on the issue, which found a healthy majority in favor of legalization, "There are big differences on age, region, party ID, and gender, with senior citizens, Republicans, and Southerners the only major demographic groups who still oppose the legal use of pot." So: old people, Republican party identifiers, and Southerners are opposed. And there's going to be a GOP presidential candidate willing to contradict those voters? Not on your life.
But for Democrats, it's a more complicated story. There's a safe position to take right now, which is some kind of middle way, the "I understand where you're coming from, and I support medical marijuana with strict regulations, but I just can't bring myself to support full legalization" position. And what does that remind you of? It's where Democrats were on gay marriage between 2004, when everybody finally had to take a stand, and 2010 or so.
At the beginning of the 2004 campaign, even support for civil unions was considered a radical position. But then it became a topic of genuine debate, and by the end of that campaign, the default position for Democrats was support of civil unions but opposition to full marriage equality. Then we kept on debating it, public opinion kept moving, and today, there is not a single Democrat with national ambitions who doesn't support full marriage equality.
I'm not saying that by the end of the 2016 race every Democrat will support legalization of marijuana for recreational purposes. But what the experience of same-sex marriage tells us is that when opinions about an issue are changing, politicians change too. And that means that where a candidate stands right now may or may not tell us where he or she will stand two years from now. So my guess is that all the Democrats will support some kind of legalization. The more tentative ones may support an extremely limited medical legalization of the kind that now exists in the District of Columbia, where there are only a few approved conditions (and a grand total of 120 people have signed up). Others may favor a looser medical legalization that is still limited in some way. But I'll bet some Democratic candidate, maybe one who's "serious" but is still an underdog and thus has little to lose, will come out in favor of legalization.