Let’s spare a thought for those of our long-suffering readers disoriented from turning on the Republican National Convention to find the leader of the International Brotherhood of Teamsters denouncing corporate giants. Let us commend to those readers the most famous of the Wall Street Journal editorials that won Bob Bartley the Pulitzer. He was America’s most free-market oriented editor. The editorial was headlined “Down With Big Business.”

It’s not our intention to suggest here that The Great Bartley and the Teamsters’ boss, Sean O’Brien, were making the same point. There are a lot of differences between the two. Yet Bartley’s scoop was that big business is not necessarily the friend of free markets. What he wanted to do was to understand why, as he put it in the editorial, “the very biggest businesses are such unreliable allies in the fight to preserve a free enterprise economy.”

Bartley’s point resonates anew after Mr. O’Brien’s speech and President Trump’s choice of Senator Vance as his running mate. Politico reckons that the choice moves the GOP “further away from its traditional pro-business ethos” toward “a populist approach that’s more skeptical of corporate power.” This shift — nascent though it may be — unsettles some pro-free market conservatives. As does Mr. Vance’s support for President Biden’s trust-busting. 

Economist Veronique de Rugy is among those raising concerns about the GOP neo-populists, and, in particular, Mr. Vance, who favors more regulation of, say, railroads and credit card issuers. Such government interference, Ms. de Rugy contends, misallocates resources and harms growth. “Central planning fails,” Ms. de Rugy explains, “because its success would require the mind of God, yet planners are human.” 

Ms. de Rugy is not the first to point out that the GOP populists are making common cause with leftists like Senators Warren and Sanders. That underscores the long history of bipartisan cronyism between big government and big business. As Bartley pointed out in 1979, big corporations can most easily accommodate regulations. Small businesses — scrappy innovators who power economic growth — get stifled by job-killing costly federal mandates. 

In Bartley’s day, behemoth General Motors was all too happy to have federal emissions standards imposed on its vehicles. Underdog Chrysler opposed them. The regulations went ahead. They hardly made a dent in GM’s bottom line. The result, Bartley lamented, was that “consumers have had to shell out millions more for their autos, and the auto marketplace has become increasingly difficult.” Potentially better anti-pollution strategies were abandoned.

Bartley’s insight, akin to Ms. de Rugy’s, was that “capitalist economies have prospered through competition, innovation,” and the free market. He described it as “a sensitive price mechanism transmitting unimaginably efficient signals.” He warned that “if you freeze the system you will lose its thrust toward progress,” even if, for giants like GM, “life will be easier.” Concluded Bartley: “Don’t look to big business for unequivocal defenses of capitalism.”

Which brings us back to the rousing speech by the Teamsters’ boss at a Republican convention. It’s going to take some careful campaigning to walk this particular line between free markets and corporate power. While it might be tempting to secure the backing of union members and other working Americans, these voters are most likely to be harmed in the long run by economic mistakes like over-regulating free enterprise.

Let us add that the Sun is not anti-union, per se. On the contrary, we have long supported the right of labor, like the right of capital, to organize. Moreover, we have praised the Teamsters’ Jimmy Hoffa, who struck the brotherhood’s greatest achievement — the Master Freight Agreement. It helped usher millions into the American middle class and ranks with some of America’s greatest parchments, along with, we have said in the spirit of exaggeration, the Association Compact.

Our point here is that we’re not inclined to freeze up over the rhetoric erupting at the GOP convention. For the most part, it’s what conventions are for — to nominate a ticket and get democracy’s greatest debate off to a rousing start. There will be plenty of time for filling in details and revisions and endorsements. And to remember that at the end of the day we attach ourselves not to men but to principles.