When Jude Wanniski died of a heart attack two weeks ago at the age of 69, my first thought was that it marked the end of the “supply-side” era. But then Jude himself would never have been so pessimistic.

The supply-side era began in earnest with the advent of Ronald Reagan and his tax-cutting, sound-money policies aimed at reinvigorating America’s entrepreneurial spirit. Jude, a friend and colleague, had been among the earliest heralds of the idea that the “demand side” policies stemming from the New Deal, typified by attempts to redistribute wealth from the wealthy to the poor, should be replaced by an approach that emphasized growth and opportunity for all.

In 1978, while still an editorial writer at The Wall Street Journal, Jude summarized and propounded the new approach in a book titled “The Way the World Works” (Regnery Publishing). The over-the-top title, reflecting Jude’s natural exuberance, earned him huge heaps of scorn from the economics and media establishment. They didn’t need the world explained to them by such a rank amateur, thank you very much.

But Jude had a very persuasive ally: reality.

We think the last few years have been rough, but the 1970s amounted to an economic storm the likes of which hadn’t been seen since the Great Depression. Several savage recessions, combined with the highest inflation of the 20th century, had sapped the nation’s confidence. By 1980, Rep. David Stockman of Michigan was warning of “an economic Dunkirk.”

The experts to whom most of the media turned for guidance insisted on more of the same castor oil: higher taxes, to keep the deficit under control, and looser money, to stimulate spending.

But Jude was, among other things, a great reporter. When he learned that some economists like Canadian Robert Mundell, who would later win a Nobel Prize, and his American protege, Arthur Laffer, a former chief economist of the White House budget office, were advocating a contrary approach, Jude wanted to know more. He schooled himself in their theories that lower taxes and tighter money could reverse the stagflation of the 1970s.

Jude wrote editorial after editorial about how tax-cutting periods like the 1920s and 1960s were closely correlated with high growth. He wrote editorials about how countries with high tax rates tended to have stagnant or declining economies. He argued that government failure, not market failure, was behind the Great Depression. He loved (as did Reagan) to quote John F. Kennedy’s aphorism that “a rising tide lifts all boats.”

And he was quick to salute a growing number of converts.

“Stupendous Steiger,” he headlined an editorial after a Congressman of that name proposed cutting capital gains taxes in 1978. “Bravo Brodhead,” he saluted Michigan congressman William Brodhead, a Democrat, for allowing a crucial vote to cut the absurdly high top income tax bracket of 70 percent to 50 percent.

Like all crusaders, Wanniski had a difficult time knowing when to stop. He was always looking for the next crusade; even some of his friends came to see him as a nattering nabob of optimism. Among other things, he managed to persuade himself that he could somehow convert Louis Farrakhan to the supply-side, arguing that the only path to prosperity for black America was a rapidly growing economy, not reliance on government redistribution.

But optimism and compassion are hardly the worst sins. Jude, who grew up in a working class home and cared deeply about the less fortunate, deserves to be remembered as one of those rare journalists who understood that ideas are news, too. As a result, he helped make a real difference in the nation’s life – a difference, I would argue, much for the better.

Mr. Bray is a Detroit News columnist.