Senate Democrats reintroduced broad legislation on Wednesday to legalize cannabis on the federal level, a major policy shift with wide public support, but it is unlikely to be enacted this year ahead of November’s elections and in a divided government.

The bill, which amounts to a Democratic wish list for federal cannabis policy, would end the federal prohibition on marijuana by removing it from a controlled substances list. The government currently classifies the drug as among the most dangerous and addictive substances.

The legislation would create a new framework regulating cannabis and taxing the burgeoning cannabis industry, expunge certain federal marijuana-related offenses from criminal records, expand research into marijuana’s health impacts and devote federal money to helping communities and individuals affected by the war on drugs.

The measure, which was first introduced in 2022, was led by Senators Chuck Schumer of New York, the majority leader; Ron Wyden of Oregon, the chairman of the Finance Committee, and Cory Booker of New Jersey. Fifteen other Senate Democrats have signed on as co-sponsors.

“Over the decades, millions of Americans, most often Americans of color, have had their lives derailed and destroyed by our country’s failed war on drugs,” Mr. Schumer, the first majority leader to call for federal legalization, said on the Senate floor on Wednesday. “In place of the war on drugs, our bill would lay the foundation for something very different: a just and responsible and common-sense approach to cannabis regulation.”