Virginia House Speaker William J. Howell (R-Stafford) listens to debate in the House of Delegates in Richmond in January 2015. (Bob Brown/Associated Press)

IN APRIL, Gov. Terry McAuliffe (D) ordered voting rights restored to 206,000 ex-convicts in Virginia, a move in line with similar recent reforms in more than 20 states that have lifted the stigma of disenfranchisement from citizens who have served their sentences and paid their debts to society. The fact that Virginia’s list of newly eligible voters was prepared in haste and that it contained errors — including murderers still behind bars — is evidence of incompetence and slapdash execution. It is not an argument that the order is illegal or unconstitutional, as critics would have Virginians believe.

Those critics, including top Republicans in Richmond as well as some prosecutors, insist that the state constitution allows the governor to restore voting and other civil rights to ex-convicts only on an individualized basis. As evidence, they point to the actions of recent governors who, while seeking to expand and accelerate the restoration of voting rights to former inmates, refrained from establishing a fully automatic system for doing so.

Yet no language in Virginia’s constitution tied the hands of former governors, or ties the hands of Mr. McAuliffe from ordering a wholesale restoration. Critics such as House Speaker William J. Howell (R-Stafford) assert Mr. McAuliffe overreached by forgoing a “case-by-case” review, but those words do not appear in the constitution. That’s also the view of the commonwealth’s foremost authority on the constitution, University of Virginia law professor A.E. Dick Howard, who, as director of the commission charged with revising the constitution nearly 50 years ago, was its primary draftsman.

Mr. McAuliffe’s critics are surely right that politics partly drove the governor’s decision, in an election year, to reenfranchise a cohort likely to vote heavily for his ally Hillary Clinton, the presumptive Democratic presidential nominee. It is equally true that politics — specifically, the racial politics of disenfranchising black voters, who make up about half of the felons on Mr. McAuliffe’s list — are driving GOP opposition. The Republicans’ stance is of a piece with their efforts to tighten voter-ID laws — another move designed to minimize the political clout of minorities in Virginia, a critical swing state.

The mistakes in the list are now fodder for a legal challenge led by Republicans, set to be heard in the state Supreme Court this month, as well as scaremongering by GOP operatives warning that murderers and rapists will flood the polls and dominate juries in criminal trials. This is false. The initial list did include some murderers still behind bars, mainly in other states, plus some 132 sex offenders confined by civil commitments — and Mr. McAuliffe removed those names from the list as soon as they came to light.

It seems far-fetched to imagine that the legal challenge will succeed. The state Supreme Court would have to concoct a constitutional interpretation without grounding in actual language and accept the premise that administrative errors somehow negate the governor’s authority. If his critics prevail, however, Mr. McAuliffe will be within his rights to press his signature machine into overtime signing 206,000 “individualized” restoration orders, as he has said he might do.