The top Senate Democrat is using marijuana’s informal holiday to announce a change of heart about the drug, another sign of the growing political acceptance of pot.

Senate Minority Leader Chuck Schumer of New York said Friday he’ll introduce a bill taking marijuana off the federal list of controlled substances — in effect decriminalizing its use.

His bill would let states decide how to treat marijuana possession. Under the measure, the federal government would still enforce laws against moving pot into states where it’s illegal and would still regulate advertising so it isn’t aimed at children. Schumer said he also wants to ensure that minorities and women have a fair shot at getting involved in the growing marijuana industry and that the federal government invests in research to better understand the drug’s health effects.

“My thinking, as well as the general population’s views, on the issue has evolved,” Schumer said.

Schumer is only the latest mainstream politician to endorse what once was viewed as a pet cause of stoners and ex-hippies. But as more and more states legalize some marijuana use and an industry is beginning to boom around its sale, powerful politicians in both parties are shifting their stances and seeing the political benefits.

Schumer unveiled his new position on HBO’s “Vice News Tonight” where he was asked whether he had smoked pot before. “No,” he replied.

Would he like to try? “Well, as you pointed out maybe I’m a little old. But, who knows? Who knows?” said Schumer, age 67.

Schumer timed his announcement to April 20, or 4/20. That’s the numerical code for marijuana’s high holiday, an homage to pot’s enduring appeal and universal slang for smoking.

Schumer’s new stance could be a smart move politically. Democrats are trying to do a better job of connecting with young voters, hoping to drive them to the poll in November’s…