PHILADELPHIA — First, 20 states and the District of Columbia passed laws legalizing marijuana for medical use.

Then in 2012, voters in Washington state and Colorado approved measures legalizing the sale and possession of marijuana for non-medical use, with state oversight.

Now at least a half-dozen states from Alaska to Maine are considering following suit.

Marijuana still remains a federally controlled substance, but Attorney General Eric Holder in January said the Justice Department would soon issue regulations to let state-sanctioned marijuana businesses have access to banking and credit.

Can full legalization be far behind? Ben Boychuk and Joel Mathis, the RedBlueAmerica columnists, try to wrap their heads around the question.

BEN BOYCHUK

The University of Colorado system reports a 30 percent increase in applications this year. University officials credit their new and improved application, along with better high school outreach.

But High Times magazine, a sort of Cigar Aficionado for stoners, has a different explanation: It’s the legal pot.

Can that really be true? A CU spokesman told the magazine he has a “hard time believing that someone is going to make that kind of significant decision about investing in their education based on whether they can smoke marijuana in the state” – which only suggests he hasn’t visited his Boulder campus recently, or knows very much about the law of unintended consequences.

More kids looking for a cheap and legal high are one such consequence.

Here’s another: If you smoke pot and want to buy a gun in the Mile High State, odds are you will be turned down. Sure, marijuana use is legal under state law, but the federal government still considers it a crime, and no federally licensed firearms dealer would risk his business to make a point about states’ rights.

Fact is, Congress isn’t about to legalize pot, and Eric Holder won’t be attorney general forever. More states venturing down the path of legalization invites conflicts with the feds that nobody can foresee.

It may be the case that public opinion has shifted too far in favor of legalization. If so, then freedom must come with responsibility.

Tax marijuana, certainly, but also let employers decide whether they want stoners on their payrolls, lay heavy penalties on sales to minors – and hope the unintended consequences aren’t too dire.

JOEL MATHIS

Consider the following facts, courtesy of the American Civil Liberties Union:

“Every 0.01 hours someone in the United States is arrested for having marijuana; black people are 3.73 times more likely to be arrested than white people. The United States spent $3.6 billion enforcing marijuana laws in 2010.”

Worth it? Almost certainly not.

Why? Marijuana may be illegal, but it’s also pretty mainstream: A 2013 Gallup poll suggests that 38 percent of Americans have tried marijuana, a number that has little changed since the “Just Say No” reefer madness of the 1980s.

And while Ronald Reagan had to withdraw a Supreme Court appointee who admitted smoking pot more than a decade earlier, these days there’s hardly anybody at the forefront of public life who won’t admit having dabbled with doobies in their youth.

The republic survives.

There are concerns that legalized pot would somehow rob America of its vigor: “How many people can get stoned and still have a great state or a great nation?” California Gov. Jerry Brown asks.

Brown’s rationale is almost exactly the same as was used for the failed prohibition of alcohol in the 1920s. We never learn.

Criminalizing weed makes hypocrites out of otherwise law-abiding Americans, reduces respect for the law, and saddles our nation with the expense of prosecution and prison for folks who pose very little threat to society.

Thank goodness for the legalization movement.

— McClatchy/Tribune