What does broccoli have to do with health insurance?

Until recently, nothing. Now, perhaps a lot.

Broccoli, of all things, came up in the Supreme Court during arguments over the constitutionality of the Obama administration's health-care law. If Congress can require Americans to buy health insurance, Justice Antonin Scalia asked, could it force people to buy anything — including a vegetable that many find distasteful?

"Everybody has to buy food sooner or later," he said. "Therefore, you can make people buy broccoli."

Since then, broccoli has become the defining symbol for what may be the most important Supreme Court ruling in decades, one that is expected any day and could narrow the established limits of federal power and even overturn legal underpinnings of the New Deal. If the court strikes down the health-care law — which many constitutional experts, both right and left, long doubted it would do — many lawyers say one reason may be the role of broccoli in shaping the debate.

Broccoli did not spring from Scalia's mind. The vegetable trail leads backward through conservative media and pundits. Before reaching the Supreme Court, vegetables were cited by a federal judge in Florida with a libertarian streak; in a Web video financed by libertarian and ultraconservative backers; at a congressional hearing by a Republican senator; and a column by David Rivkin Jr., a libertarian lawyer whose family emigrated from the former Soviet Union when he was 10.

Even those who reject the broccoli argument appreciate its simplicity. Whatever the Supreme Court rules, the decision has become a cliffhanger that few believed possible.

"I have some grudging admiration for them," said Akhil Amar, a professor of law and political science at Yale and author of a book on the Constitution. "All the more so because it's such a bad argument. They have been politically brilliant. They needed a simplistic metaphor, and in broccoli they got it."

The seeds of the broccoli debate date to the early 1990s, when President Clinton first proposed a universal health-care plan that required all businesses to provide health insurance. "How can the government do that?" Rivkin wondered.

He attended Georgetown University, later worked in the White House Counsel's Office under President George H.W. Bush and now, at 55, is a partner in the Washington, D.C., office of a law firm.

"I'm driven by two things," Rivkin said. "Enormous appreciation bordering on burning love for the American system. ... And a healthy suspicion of governmental power, having come from an environment where you had an all-powerful totalitarian government."

With law partner Lee Casey, Rivkin took aim at the commerce clause of the Constitution. It had become the source of ever-expanding legislative power since Chief Justice John Marshall wrote in 1824 that congressional power to regulate commerce "may be exercised to its utmost extent."

In a September 1993 commentary in The Wall Street Journal, Rivkin and Casey argued the Clinton proposal was unconstitutional. Requiring Americans to buy insurance went a step beyond a famous 1942 case, Wickard v. Filburn, long a thorn in the side of those who opposed the New Deal. In it, the Supreme Court ruled Congress could prevent a farmer from growing wheat for his consumption on the theory that any wheat affected the total supply, and thus fell within interstate commerce.

The health-care law, the lawyers maintained, did not ban an existing activity such as growing wheat, but forced people who were doing nothing to act in a certain way. If Congress could regulate inactivity, they argued, there might be no limit to what it could force people to do.

The Clinton administration's health-care effort collapsed, but Rivkin's unorthodox theory lived on.

By 2009, with the Obama administration pushing its health-care initiative, one that included a requirement that Americans buy health insurance, Rivkin and Casey returned to The Wall Street Journal and Washington Post op-ed pages. Rivkin also took his argument to Sen. Orrin Hatch, R-Utah.

Hatch had supported an individual mandate as an alternative to a more sweeping plan championed by Hillary Rodham Clinton. After listening to Rivkin, though, the senator embraced the argument.

"If we have the power to simply order Americans to buy certain products, why did we need a Cash for Clunkers program or the upcoming program providing rebates for purchasing energy-saving appliances?" Hatch asked during hearings in October 2009. "We could simply require Americans to buy certain cars, dishwashers or refrigerators."

His remarks struck a chord with Terence Jeffrey, editor-in-chief of CNS News, a website once known as the Conservative News Service. Both his parents are doctors, and he has an interest in health care.

But he figured most Americans would not understand an abstract debate over the limits of the commerce clause. Searching for an easy-to-grasp analogy, Jeffrey hit upon something "that would go more to health care, something that people would universally recognize was good for you."

Broccoli.

"I know George Bush didn't like broccoli. It seemed an obvious thing that everyone thinks is good for you."

Obama's health-care law passed on March 21, 2010. That summer, after Solicitor General Elena Kagan was nominated to the Supreme Court, the subject of vegetables resurfaced in confirmation hearings. Sen. Tom Coburn, R-Okla., also a doctor, asked, "If I wanted to sponsor a bill and it said, 'Americans, you have to eat three vegetables and three fruits every day,' and I got it through Congress and it's now the law of the land, got to do it, does that violate the commerce clause?"

"Sounds like a dumb law," Kagan replied.

The exchange caught the attention of Austin Bragg, 33, a producer for Reason TV. He proposed a video Reason TV and its magazine and Internet outlets are subsidiaries of the Reason Foundation, a libertarian research organization whose largest donors are the David H. Koch Charitable Foundation and the Sarah Scaife Foundation. Both finance conservative and libertarian causes.

The video, "Wheat, Weed and Obamacare: How the Commerce Clause Made Congress All-Powerful," was shown on YouTube and the Reason website in August 2010.

In the video, Coburn asks Kagan about eating vegetables and fruits, and cuts to Erwin Chemerinsky, a liberal and dean of the law school at the University of California, Irvine.

He appears to struggle with the question of limits to congressional power, saying at one point, "Congress can force economic transactions," and at another, "power can be used in silly ways, and the Constitution isn't our protector."

For Gillespie, the video had the desired effect.

"Based on that video, Chemerinsky is the best screen villain since Hannibal Lecter," he said. "But he got his chance to make his case."

At this point, different strands of the broccoli legal argument came together. It happened in a suit filed by the state of Florida that challenged the constitutionality of the health-care law. (Florida eventually was joined by the attorneys general of 25 other states, including Washington's Rob McKenna.)

Arguing the case was Rivkin. He and Casey had been hired by Florida's attorney general, who had read their Wall Street Journal articles.

U.S. District Judge Roger Vinson, an appointee of President Reagan, heard the case, and introduced the subject of broccoli. "If they decided that everybody needs to eat broccoli because broccoli is healthy, they can mandate that everybody has to buy a certain quantity of broccoli each week?" he asked.

(Vinson didn't respond to the question of where he came up with broccoli, but Rivkin said he thought he had mentioned it to the judge. Vegetables also surfaced during oral arguments in a Virginia case, when the judge asked if people could be forced "to buy an automobile, to join a gym, to eat asparagus.")

Ian Gershengorn, a Justice Department lawyer who argued the Florida case, replied: "But what this case is about is the purchase of a very particular product, and it is not shoes, it is not cars, it is not broccoli."

That argument summed up the prevailing view among legal scholars, but broccoli figured prominently in Vinson's ruling that the law was unconstitutional, as did the Reason video.

Broccoli quickly became the defining symbol for the debate. Fox News led its report on Vinson's opinion with a broccoli reference. Hits to the Reason video increased. Rush Limbaugh took up the issue.

Scalia's broccoli question suggests the argument struck a chord with him, too. It also seems to have resonated with Justice Anthony Kennedy, widely viewed as the swing vote.

"The government is saying that the federal government has a duty to tell the individual citizen that it must act, and that is different from what we have in previous cases," Kennedy said, echoing Rivkin's argument.

Legal scholars say it is hazardous to predict how the court will decide. Whatever the outcome, that such a small group of libertarian lawyers could harness the power of media in the digital age and have such an impact "has left the legal establishment reeling," Cato's Shapiro said.

Seattle Times staff contributed

to this report.