Hillary Clinton's approach to marijuana legalization can best be described as a cautious, leave-it-to-the-states strategy similar to that of the Obama administration. But her wary approach to the issue puts her at slight odds with most voters, more of her Democratic base, and even most voters in some key swing states, all of whom flat-out support legalization.

In her most recent comments on the issue during a CNN town hall last June, Clinton said, "On recreational, you know, states are the laboratories of democracy. We have at least two states that are experimenting with that right now. I want to wait and see what the evidence is."

Asked about her views on medical marijuana, Clinton also took an ambiguous stance: "I don't think we've done enough research yet. Although I think for people who are in extreme medical conditions and have anecdotal evidence that it works, there should be availability under appropriate circumstances. But I do think we need more research, because we don't know how it interacts with other drugs. There's a lot we don't know."

The stance is not out of step with many politicians. The Obama administration, for example, has allowed Colorado, Washington state, Alaska, and Oregon to legalize marijuana without much federal intervention — all while the administration officially opposes legalization. But Clinton's position, just like President Barack Obama's, is different from where many in the public already are right now.

Marijuana legalization is popular, particularly among Democrats

Most Americans are in favor of legalizing marijuana. According to decades of surveys from Gallup, support for legalization rose from 12 percent in 1969 to 31 percent in 2000 to 51 percent in 2014. A Civic Science poll and the General Social Survey found similar levels of support in 2014.

Millennials are particularly strong advocates of legalization, according to a 2014 survey from the Pew Research Center. But there's also majority support among Democrats in the three youngest generations in the US today.

Marijuana legalization also appears to be favored in several swing states. A Quinnipiac University survey conducted in March found a majority of voters support full legalization in Florida (55 percent), Ohio (52 percent), and Pennsylvania (51 percent) — all key states that a Clinton campaign may need to win the general election.

Medical marijuana, meanwhile, has even greater backing from people of all ages and political parties. A 2010 Pew Research Center survey found that 73 percent of American voters back medical marijuana, including 80 percent of Democrats. Support has presumably grown since 2010 — but even if it hadn't, Clinton's cautious medical marijuana stance would stand in sharp contrast with four in five Democrats.

Clinton's stance to let states decide whether to legalize is "unnecessarily tepid for a Democrat," Dan Riffle, director of federal policies at the Marijuana Policy Project, told me in an email. "There's nothing to lose and a lot to gain for her if she were to take a more aggressive position in favor of regulation. By not doing so, she leaves the door open for a candidate like [former Maryland Gov. Martin] O'Malley, who is trying to outflank her with liberals and young voters, to make marijuana reform part of his platform."

Clinton's position ultimately may not matter

Voters in four states and Washington, DC, have fully legalized marijuana, and 19 more states allow it only for medical purposes. And advocates plan to put legalization on the ballot in at least five states in 2016, the same year Clinton would appear on the ballot.

If this trend toward legalization continues, it might not matter if Clinton just leaves the issue to the states. Many pro-legalization advocates argue that the most important thing a president can do right now is let states carry out their laws without federal intervention — just like the Obama administration has done.

"All we really need from the next administration is to respect state marijuana laws," Riffle said. "Once those laws are implemented and the public can see how much more effective regulation is compared to arresting and prosecuting adults and letting criminals run the market, support will grow as it has in the wake of Colorado effectively implementing its law."