“If the prosecutor is obliged to choose his cases, it follows that he can choose his defendants. Therein is the most dangerous power of the prosecutor: that he will pick people that he thinks he should get, rather than pick cases that need to be prosecuted.”

We have several times cited that warning from Attorney General Robert Jackson’s famous speech in 1940. It has rarely seemed more relevant, though, than now, as the District Attorney of New York County, Alvin Bragg, reportedly prepares to seek an indictment of the ham sandwich of President Trump.

That’s a reference to Judge Sol Wachtler’s crack about how a prosecutor could get a grand jury to indict a ham sandwich. The way Jackson put it is that “a prosecutor stands a fair chance of finding at least a technical violation of some act on the part of almost anyone.” 

“In such a case,” Jackson said in his famous warning, “it is not a question of discovering the commission of a crime and then looking for the man who has committed it, it is a question of picking the man and then searching the law books, or putting investigators to work, to pin some offense on him.”

This is why the Wall Street Journal, one of Mr. Trump’s most principled critics, is this morning warning that it is “impossible to overstate Mr. Bragg’s bad judgment here.” The DA is preparing to indict, for the first time in history, a former president and on a misdemeanor he’s trying to bump up to a felony.

All that is an astounding example of the boast of the head of Soviet Russia’s secret police, Lavrentiy Beria. “Show me the man,” Beria is said to have bragged, “and I’ll show you the crime.” In this case it’s unfolding in broad daylight against a man who, in Mr. Trump, is the leading contender to be the Republican nominee for president.

Netflix couldn’t make this stuff up, and Americans are left to wonder whether an indictment of Mr. Trump, under the circumstances Mr. Bragg seems to be contemplating, would help the former president in his campaign for a second term. We don’t mind saying that on this question we’re parve.

We’d take caution, though, from the phenomenon of Eugene Victor Debs, the only candidate of what we called a significant party — in his case, the Socialists — to stand for president from a prison cell. The “high-minded Hoosier,” as we called him a year ago, agitated against the draft and went to the big house for sedition.

Then the surprise. “As inmate number 9653 at the penitentiary at Atlanta,” we wrote a year ago, Debs “was in 1920 nominated by the Socialist party as its candidate for president. He was permitted to make one public statement each week during the campaign.” He railed against President Wilson as “a tool of Wall Street.”

In the election, he received a share of the ballots that today would have netted him something like 5.3 million votes. President Harding commuted Debs’ sentence, and he left prison to the cheers of his 2,300 fellow inmates — and went on to be received at the White House by, in Warren Harding, a Republican president.

God bless America, we say. Will such a scenario play out for President Trump?  We don’t know. We do know, though, that the American people are not dumb. They know an abuse of power when they see it. We like the way the question was put the other day in these columns by Alan Dershowitz.

“Does anyone actually believe that if someone else were accused of paying hush money to avoid a sex scandal in the manner that Mr. Trump is suspected of doing, he would be prosecuted?” The answer to that question is clearly no. If Mr. Trump is charged and acquitted, where will the Democrats go to get their reputation back?