How did broccoli become the poster child of the good-for-you yet ostensibly bad-tasting vegetable? • Broccoli has long been an othered vegetable in America. As late as the 1920s, most Americans (the ones who had heard of it, anyway) associated it disdainfully with Italian immigrants, who were its primary consumers. • According to Joel Denker in The World on a Plate, it wasn't until 1928 that broccoli first was distributed regionally, and it wasn't until the mid 1940s, after intense marketing campaigns by broccoli distributors, that it gained recognition among non-Italians.
Recognition isn't the same thing as popularity, and though Americans came to eat broccoli, they didn't necessarily trust it. Broccoli remained an outsider during the canned-vegetable era of post-World War II suburban America because it's nearly impossible to can. This meant that when Americans consumed it in the 1950s and 1960s, it was usually cooked from scratch — which strengthened its association with the "well-meaning but overbearing mother figure," to quote The Rhetoric of Food editor Joshua Frye.
In 1962, the New York Times reported that Americans consumed, on average, 7 pounds of carrots but only 1 pound of broccoli per year. Over the next couple of decades, broccoli earned a bit of hippie cred: It rated very highly on Frances Moore Lappé's most protein-efficient vegetables chart in her vegetarian treatise Diet for a Small Planet and took a starring role in Mollie Katzen's meatless cookbook The Enchanted Broccoli Forest.
But broccoli didn't become a conservative rhetorical weapon until 1990, when then-President George H.W. Bush declared, "I do not like broccoli, and I haven't liked it since I was a little kid and my mother made me eat it, and I'm president of the United States, and I'm not going to eat any more broccoli." It was a conflation of American freedom and childish rebellion, and it set off a brief firestorm in the media (and prompted a tongue-in-cheek shipment of broccoli to the White House from the United Fresh Fruit and Vegetable Association).
Of course, the 41st president of the United States is not the only broccoli hater out there. Considering broccoli's unique dual texture (dense, sometimes stringy stalks and clustered, frilly florets) and the fact that it's difficult to disguise said texture, it's no surprise broccoli has a bad rap among kids (who have a natural aversion to bitterness) and picky adults. And unlike spinach, which earned considerable points among children when Popeye entered the scene, broccoli has never gotten a pop culture reprieve.
Though the Supreme Court justices made the forced-broccoli-buying scenarios about as dry as possible in their opinions on the health care act, the function of the metaphor as a rhetorical device is clear: It attempts to make listeners feel like kids at a dinner table, being coerced into doing something they don't want to do by their overbearing mom.