The allegation is “impermissibly speculative,” U.S. District Judge James C. Mahan said in a ruling Friday in Las Vegas.

“The state of Nevada has its own mechanisms for deterring and prosecuting voter fraud,” Mahan, an appointee of President George W. Bush, said in the decision.

The ruling is the latest legal setback for Republicans, who have sued or intervened in cases across the U.S. challenging measures intended to increase mail-in voting during the pandemic. In several cases, judges have noted that allegations of rampant fraud tied to mail-in voting weren’t backed up with evidence.

The campaign cited studies and news articles on fraud to make its case, describing “a parade of administrative problems” with mail-in voting expansions in Wisconsin, New Jersey, Connecticut and New York due to the coronavirus pandemic, according to the ruling. But Mahan said the claims amounted to a “generalized grievance about the conduct of government.”