President Trump has more detail to provide on what he means by a “major investigation” into voter fraud. Already, however, he has drawn sharp objections to his preoccupation with illegal voting, including from within his own party and the National Association of Secretaries of State, on the basis that there is no evidence to support his claim. His own press secretary seems to have retreated to the position that “he [the president] believes what he believes.”

But it cannot be lost in this debate that the President is taking an extraordinary step with the contrivance of some sort of “investigation,” whatever the form takes. He is moving, openly and aggressively and within days of his inauguration, to use his public office to advance his personal political interests as a candidate for office. One such interest, apparently, is to contest the popular vote count of the 2016 general election–his election. The second, it is fair to assume, is to do everything necessary to establish the fraud he is convinced is rampant and push for measures he deems helpful to his next election campaign.

The first of these objectives is quirky. It is not the usual course of events that a candidate challenges the outcome of an election that he won. But it is still his own election and he intends now, as President, to put the 2016 popular vote margin in question for his own political benefit, to satisfy–as he sees it–a political need.

The second of these interests is his own reelection. Until we learn otherwise, Mr. Trump will be a candidate for re-election in 2020. Now, as president, he intends to order up some investigation with implications for this candidacy. Critical commentators have touched on this concern to some degree, warning that this investigation might be intended to feed into the broader GOP initiative on voter ID and other restrictions on the franchise. The investigation would serve to spur proposals for further additional restrictions that, while unwarranted as policy but designed to burden voters, could discourage or impede voting primarily in communities with high Democratic support. This is a possible, perhaps even a likely, outcome, and it both deeply objectionable and sure to spark a new round of voting rights litigation. But the context in which the President has raised the issue is not his party’s programmatic attention to voter fraud, but his election, the 2016 election, and his conviction that it cost him millions of votes.

In recent years, three different Commissions have formed to look at problems with the electoral process: Carter-Ford (2001), Carter-Baker (2005), and the Presidential Commission on Election Administration (2015). In both Carter-Ford and Carter-Baker, the sponsors were universities with financial support from foundations. The Presidential Commission was set up by Executive Order by a sitting President, but after his career as an active candidate ended with his 2016 re-election. Of course, in all arguments over electoral reform, partisan conflicts can flare up and politics can influence, subtly or more overtly, the subjects picked for examination and the shape of the recommendations. Precisely for that reason, the Presidential Commission steered carefully around issues, like voter ID, most certain to be caught up in political or ideological pressures.

In none of these prior Commissions, however, did a candidate with a direct personal interest in the outcome conceive of the project and set it into motion–and do so after prejudging the conclusions.

Rick Hasen lays out the requirements for a new Commission that would look fairly and therefore credibly into this claim of fraud. He is highly skeptical that Mr. Trump would establish a Commission that met these standards. But he does not entirely write off the possibility that with appropriate bipartisan leadership and expert staffing, and with a mandate to examine both illegal voting and vote suppression produced by unjustified “anti-fraud” measures, “this call for a major investigation, if done fairly, could finally put the issue to bed.”  But the problem with any inquiry set up by this President is the source –a candidate for office, with clear political interests and a repeatedly stated, unshakeable belief in what the conclusion should be. It is difficult to see who, with the credibility and expertise needed for this enterprise, would–or should–agree to participate under these conditions.

A popular explanation, tending to minimize the ethical issue, is that this is all a matter of presidential personality or psychology. But the ethical issue becomes unavoidable if the original impulse, if that is what it was, is now replaced by an investigation; if the tweet now turns into an Executive Order or other official directive.

The recurrent emphasis on the President’s volatility, while a reasonable enough concern, allows attention drift too far from a core problem: abuse of official position. Presidents are skilled politicians who keep close watch on their political well-being as they formulate policy and make decisions, but there are limits, and crucial are those constraints having to do with the misuse of official authority to improve their electoral prospects.

The President is entitled, of course, to “believe what he believes.” He is free to make the case for an inquiry into the voting fraud. But once he has made it, he should stand aside and leave the choice of proceeding to others, to experts and election officials, outside his Administration. The President has been heard on this subject. The best course for him now is the functional equivalent of recusal.