SINCE SAN FRANCISCO first moved in 2007 to staunch the deluge of non-biodegradable shopping bags that harm wildlife and litter streets, waterways and sewers, other jurisdictions have followed suit, including the District, three years ago, and Montgomery County, last year. As the use of 5-cent bag taxes and similar measures have spread, Americans have learned two lessons: The measures are effective at cutting litter and popularizing the reuse of bags; and industry arguments against such measures are nonsense.

That has raised hopes in Maryland of enacting the country’s first statewide bag taxthis year. (Hawaii has a de facto ban, since each of its four countiesprohibits the use of carryout plastic bags at checkout counters.) Predictably, plastic-bag manufacturers are again hoping to kill or subvert legislation that would benefit the environment.

The evidence from the District and Montgomery is overwhelming. In the District, plastic bag use has dropped by at least half since the 5-cent tax went into effect in 2010. In Montgomery, the drop was significant — about a third — though not as sharp as in the District; however, the county collected more than $2 million from the tax last year, which will help it pay to remove litter that includes plastic bags.

In Annapolis, some state lawmakers, under the sway of industry lobbyists, advance the bogus, racially tinged argument that low-income residents oppose the proposed nickel tax — as if the poor are unmoved by the effects of environmental degradation.

On Thursday, two D.C. Council members, Marion Barry (D-Ward 8) and Tommy Wells (D-Ward 6), performed a service by puncturing that particular myth. “None of us want this litter in our community,” said Mr. Barry. He added: “You will hear that [the tax] is too much. But people will waste five cents on alcohol, on a lot of things.”

Opponents of the legislation have suggested that reusable bags could harbor germs. That’s news in Europe, where they have been common, and safely used, for decades. They say reusable bags might be used by shoplifters. Please.

Industry lobbyists even argue that plastic bags don’t contribute much to litter, as if the visible evidence all around — bags in tree limbs, bags blowing down the street, bags clogging sewer drains — is invented. A study by the Maryland Department of the Environment last year confirmed their harmful effects.

The bag tax legislation pending in Annapolis is projected to cut the use of carryout bags and, under one scenario, generate $7.3 million in revenue, a quarter of which would be retained by retail establishments like grocery stores. It’s a sensible measure that will help the environment — if lawmakers have the spine to stand up to special interests.