In her first economic policy speech as the 2024 Democratic presidential nominee, Kamala Harris rightly criticized Donald Trump for favoring steep tariffs, saying her Republican opponent “wants to impose what is, in effect, a national sales tax on everyday products and basic necessities that we import from other countries.” But in the same speech, Harris pitched a half-baked idea that is just as economically dubious, promising to crack down on “price gouging” by the grocery industry. That proposal is so misguided that it provoked undisguised skepticism from mainstream news outlets such as CNN, …