It’s guesswork to say how many still-undecided races would have been resolved by now had Mr. Hogan not cast that veto. Still, Mr. Hogan’s veto was a gratuitous gesture that was little more than a sop to Republican voting fraud conspiracy theorists. What’s more, the glacially slow process by which Maryland’s votes are counted will likely be repeated in the general election. That’s not just an annoyance; it also undermines voters’ faith in elections and feeds unfounded conspiracy theories.

Maryland is the only state in the country where election officials are barred from opening, processing and counting mail-in ballots until two days after primary or general elections. Once, that made little difference, because the vast majority of voters went to the polls on Election Day. That began changing a few years ago, and, with the pandemic, mail-in voting became the norm for large numbers of voters — including in the 2020 primaries, when it was nearly the only voting method feasible and available. Recognizing that, Mr. Hogan used emergency powers that year to suspend Maryland’s antiquated law so that election officials could get an early start.

In his veto letter, Mr. Hogan acknowledged that the bill would provide election officials with a “much needed head start” on processing what he called the “deluge” of mail-in ballots. And he rightly said that mail-in ballots encourage voting by making it accessible and convenient, which he said is “vital to a healthy democracy.”

He then gave specious reasons for vetoing the bill, insisting that “abuse does happen more” with mail-in voting and that “even the appearance of impropriety or the opportunity for fraud can be enough to undermine citizens’ confidence in the electoral system.”

The trouble with Mr. Hogan’s argument is that the facts don’t support it. Voting fraud or abuse, in person or by mail, is insignificant in Maryland, as in other states, as both Republican and Democratic elections officials have made clear. Mr. Hogan surely knows this, since his own logic rests on the slippery slope of “appearance” and “opportunity” for fraud.

To his credit, Mr. Hogan has staked out a political stance in opposition to former president Donald Trump. In this instance, however, he appears to be pandering to Republicans under the influence of Mr. Trump’s demagoguery. Whatever his motives, the governor, by quashing reforms to an outdated voting system, has done a disservice to Marylanders.