On marijuana policy, Bernie Sanders is closer to the Democratic base than Hillary Clinton. 

At Tuesday night's Democratic presidential debate, Sanders suggested he would vote for marijuana legalization if it came up in his state. " I suspect I would vote yes," Sanders said. " And I would vote yes because I am seeing in this country too many lives being destroyed for nonviolent offenses.  We have a criminal justice system that lets CEOs on Wall Street walk away, and yet we are imprisoning or giving jail sentences to young people who are smoking marijuana." 

Democratic frontrunner Hillary Clinton, meanwhile, suggested she's not ready to support legalization.  She said she backs medical marijuana and suggested she supports decriminalization, which would remove criminal penalties for pot but leaves civil fines in place.  But when it comes to full legalization, she said she would like to leave it to the states — for now. 

Clinton's timidity on marijuana puts her at odds not just with Sanders, but with the Democratic base, which strongly supports legalization.  But it's also unlikely Clinton's cautiousness will ultimately have much of an effect on marijuana policy. 

Democratic presidential candidates shouldn't be shy about supporting marijuana legalization

Not only do most Americans support marijuana legalization, according to Pew Research Center polls, but nearly six in 10 Democrats do — and that support climbs to more than 75 percent when looking only at millennial Democrats. 

Clinton's cautious approach is "unnecessarily tepid for a Democrat," Dan Riffle, director of federal policies at the Marijuana Policy Project, previously 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." 

So why is Clinton taking a cautious approach?  With full legalization of possession and sales still a relatively new policy in Colorado, Washington state, and Oregon, there are many concerns that something will go wrong.  Will commercialization lead to more abuse?  Will more teens try marijuana — to potentially harmful results?  Will people combine their alcohol and marijuana use, leading to even worse problems with drunk driving and other types of accidents? 

These are valid concerns.  But ultimately, they may not stop legalization from moving forward, even if Clinton is elected. 

The candidates' differences ultimately may not matter

Voters in four states and Washington, DC, have 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, including California, in 2016 — the same year a Democratic nominee will appear on the ballot. 

If this trend toward legalization continues, it might not matter much what the next president believes.  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.  After all, in a gridlocked Congress, federal marijuana legalization isn't likely to pass anytime soon, even as it moves through the states. 

"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." 

So as long as the next president doesn't tell Coloradans, Alaskans, and — perhaps after 2016 — Californians what they can do, the Democratic candidates' differences on marijuana policy might not matter.