The conviction today of the Trump Organization in a tax-fraud scheme certainly represents a remarkable moment in the epic legal campaign against the former president. Mr. Trump himself was not convicted, or even charged, in the case, but the prosecution argued at trial that he was “explicitly sanctioning tax fraud,” the AP reported, and accused the company of having a “culture of fraud and deception.”

The conviction, brought in by a jury in state Supreme Court at Manhattan, was of the corporate entity, which could end up being hit with as much as $1.6 million in penalties. That may not be much for a company as large as the Trump Organization, but it underlines the seriousness of the criminal activities and could whet the appetite of investigators to wheel on the former president himself. It’s not our intention to make light of any of it.

At the same time, the pursuit of the Trump organization and its chief financial officer, Allen Weisselberg, leaves us with an uneasy sense. It is that none of this would be in criminal court in the ordinary course of criminal justice had Democratic prosecutors not been out for the former president himself. That speaks to the danger of politicized prosecution laid out by FDR’s attorney general, and, later, a Supreme Court justice, Robert Jackson.

“With the law books filled with a great assortment of crimes,” Jackson said in remarks to prosecutors, “a prosecutor stands a fair chance of finding at least a technical violation of some act on the part of almost anyone.” This raises the danger of a prosecutor with an ulterior motive “picking the man and then searching the law books, or putting investigators to work, to pin some offense on him.”

That, Jackson warned, is where “the greatest danger of abuse of prosecuting power lies,” when “law enforcement becomes personal.” The insight resonates following today’s conviction. The outcome of the case is likely to fuel the pursuit of Mr. Trump by others, including Manhattan’s district attorney, Alvin Bragg, who just hired an ex-Justice department prosecutor to “ramp up” his office’s “investigation into the former president,” the Times says. 

The fact that the new hire, Matthew Colangelo, was an Obama administration official and had also worked on the New York Attorney General’s civil investigation of Mr. Trump made it likely to “set off protest from the former president,” the Times reported, especially since the former president has already characterized the civil and criminal investigations against him as “a unified ‘witch hunt.’”

Mr. Bragg had expressed doubts about the merits of the fraud case against Mr. Trump, prompting two senior prosecutors in his office to step down. One of them was so enraged by Mr. Bragg’s decision to hold off on the case until his team of prosecutors could nail down the charges that he leaked his retirement letter to the Times. “I believe that Donald Trump is guilty of numerous felony violations,” Mark Pomerantz wrote.

Conceding the case may have had flaws — among them the finding that the purported “victims” of Mr. Trump’s alleged fraud had profited by their dealings with him — Mr. Pomerantz said: “No case is perfect,” and averred that “a failure to prosecute” would endanger “public confidence in the fair administration of justice.” Such prosecutorial overzealousness is precisely what Jackson sought, some seven decades ago, to warn against. 

Which brings us back to the case against the Trump organization and the general sense that these charges wouldn’t have been brought against a mere citizen. We’ve just seen federal fraud and bribery charges against a former Democratic lieutenant governor, Brian Benjamin, get thrown out by a district judge. It’s a reminder that prosecutorial overreach against public officials is a problem that crosses party lines.