Some lawmakers think this is a good idea:

Senate Majority Leader Mitch McConnell, R‑Ky., announced he will introduce national legislation to raise the minimum age for people buying tobacco products from 18 to 21.

But evidence from the U.S. and elsewhere suggests the MPA-21 for alcohol has had minimal impact on drinking or driving fatalities among 18–20 year olds. And rampant evasion teaches young adults that rules are made to be broken, thereby breeding disrespect for the law.

A MPA-21 for tobacco will suffer the same fate. Worse, it would be one more step down the slippery slope toward tobacco prohibition. What could possibly go wrong?