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A federal court blocked New Hampshire’s “signature mismatch” law on Tuesday, prohibiting the state from rejecting ballots on the basis of inconsistent handwriting. The court found that election officials had violated voters’ constitutional rights by tossing out their ballots due to perceived discrepancies between signatures. In 2016 alone, officials disenfranchised 275 voters for alleged signature mismatches, a disproportionate number of whom were disabled.

New Hampshire’s bizarre mismatch rule applied to all residents who vote by absentee ballot. Voters must sign their ballots before mailing them in; a local election official known as a “moderator” would then compare the ballot signature to the signature on file. If the moderator decided the signatures didn’t match, she had unilateral authority to reject the ballot. These moderators did not have expertise in handwriting analysis and operated under no clear guidelines. Predictably, this freewheeling system produced wildly inconsistent results: In 2016, all rejected ballots came from just 26 percent of New Hampshire’s 318 polling places. It seems a handful of overeager moderators disenfranchised hundreds of voters.

In response, the American Civil Liberties Union of New Hampshire filed suit, alleging that the state’s mismatch law violated voters’ due process rights under the 14th Amendment.

(Its client, Mary Saucedo, is 95 years old and legally blind; in 2016, her ballot was thrown out for signature mismatch.) On Tuesday, U.S. District Court Judge Landya McCafferty ruled in the ACLU’s favor, describing the rule as “fundamentally flawed.” She continued:

Not only is the disenfranchised voter given no right to participate in this process, but the voter is not even given notice that her ballot has been rejected due to a signature mismatch. Moreover, moderators receive no training in handwriting analysis or signature comparison; no statute, regulation, or guidance from the State provides functional standards to distinguish the natural variations of one writer from other variations that suggest two different writers; and the moderator’s assessment is final, without any review or appeal.

These facts, McCafferty explained, are particularly troubling because the right to vote “is of the most fundamental significance under our constitutional structure.” Under basic due process principles, the government must afford voters some recourse before stripping them of this fundamental right. Yet New Hampshire does no such thing. To the contrary, the state gives voters no opportunity to “cure” a ballot that has been tossed out for signature mismatch. And its utterly arbitrary rules do not further any legitimate interest in preventing voter fraud.

Thus, McCafferty forbade the state from rejecting a ballot because of signature mismatch. Instead, a moderator who questions a voter’s signatures must contact her and allow her to “cure” her ballot. (Voters already provide their contact information when submitting their absentee ballot.) This “easy fix,” McCafferty concluded, will “reduce the risk that qualified voters are wrongly disenfranchised and bolster the State’s interests in preventing voter fraud and safeguarding voter confidence in elections.”

Tuesday’s decision is a major victory for the ACLU, which spent months investigating the mismatch issue and tracking down disenfranchised residents. (The names of voters rejected for mismatch were added to an obscure website, then scrubbed from the internet 90 days after the election.) Unfortunately, McCafferty cannot restore the many votes that were unconstitutionally discarded in years past. But her opinion precludes New Hampshire—currently ground zero in the war on voting rights—from suppressing another vote on the basis of sloppy signatures.