Hats off to Rhode Island state Rep. Teresa Tanzi (D-Narragansett and South Kingstown) for having the gumption to do what every town, every state, should have done decades ago.

Rep. Tanzi is pushing a bill that would raise the legal age for buying cigarettes from 18 to 21. Although no other state has yet taken the step, there’s a movement in this direction — over 70 Massachusetts towns and even New York City have raised the tobacco sales age to 21; the number of Massachusetts towns has risen by nearly a third since just last spring.

The logic behind her bill is so obvious that it almost goes without saying. Most smokers get hooked as young people, are more vulnerable to peer pressure at that age, and are often ill-equipped to appreciate the impact of such life-altering decisions.

“There’s very good research that decision-making among 18 to 21 year olds is still not fabulous,” Patricia Risica, professor of epidemiology, told the Brown Daily Herald.

Opponents cite familiar objections.

Big government foes say that if 18-year-olds can vote and serve in the military, they ought to be able to make tobacco decisions — even bad ones — for themselves. That same rationale was used against raising the alcohol sales age years ago.

And convenience store owners and state revenue collectors bemoan the potential loss of sales and tax revenue across state lines. It’s an especially potent argument in border towns like these.

That tax revenue argument is an especially sad one: Is that lost money (Rep Tanzi calls it a “drop in the bucket”) really worth the damage done?

The real oddity is that cigarettes are legal for any age. Given the energy with which government works to protect us from carcinogens, how is it that this one proven killer and addictive narcotic is sold right over the counter?

Limiting sales to 21 and older is a step in the right direction. With lives at stake, lost tax revenue is a shameful excuse.