In a pair of unanimous rulings, the court sided with Joseph Percoco, a former aide to Gov. Andrew Cuomo of New York, and Louis Ciminelli, a contractor in Buffalo.
In a pair of unanimous decisions in cases involving defendants convicted of fraud for actions during Gov. Andrew M. Cuomo’s administration in New York, the Supreme Court on Thursday again limited federal prosecutions of public corruption.
One case concerned Joseph Percoco, a former aide to Mr. Cuomo convicted of taking illicit payments to benefit a Syracuse-area developer.
The other involved Louis Ciminelli, the owner of a Buffalo construction firm convicted of fraud in a bid-rigging scandal in connection with Buffalo Billion, a development project championed by Mr. Cuomo, a Democrat.
The rulings were the latest in a series of setbacks for prosecutors from a court that has become increasingly skeptical of federal charges of public corruption in state government.
The question in the first case, Percoco v. United States, No. 21-1158, was whether Mr. Percoco could be prosecuted under a federal law that makes it a crime to deprive the government of “honest services” for conduct that took place after he resigned his government position to run the governor’s 2014 re-election campaign.
Mr. Percoco’s lawyers argued that the law applies only to people who exercise the authority of the government, a power they said he had lacked when he received the payments. Prosecutors said that distinction was artificial.
Mr. Percoco returned to the government about eight months after he left it, following Mr. Cuomo’s re-election.
Justice Samuel A. Alito Jr., writing for seven members of the court, said that the jury instructions in the case had been flawed and that an appeals court should reconsider the matter.
The second case, Ciminelli v. United States, No. 21-1170, concerned what prosecutors said was a conspiracy to commit wire fraud by tailoring requests for proposals for work on the Buffalo development to include qualifications that would ensure the contracts would go to Mr. Ciminelli’s firm.
The prosecutors’ legal theory was that the defendants had committed fraud by depriving the government of its “right to control” the use of its assets by failing to disclose potentially valuable information.
By the time the case reached the Supreme Court, though, the government had disavowed the theory. That made for an awkward argument when the justices heard the case in November, one focused on how and how badly the government was going to lose.
Justice Clarence Thomas, writing for the court, said flatly that “the right-to-control theory is invalid,” returning the case to the appeals court for further proceedings.
The justices do not always divide along the usual lines in public corruption cases. In 2020, the court unanimously overturned the convictions of two defendants in the so-called Bridgegate scandal, in which associates of Chris Christie, who was the Republican governor of New Jersey, closed access lanes to the George Washington Bridge in 2013 to punish one of the governor’s political opponents. That was an abuse of power, the court ruled, but not a federal crime.
Similarly, the court in 2016 unanimously overturned the conviction of Bob McDonnell, a former Republican governor of Virginia who had accepted luxury products, loans and vacations from a business executive. Chief Justice John G. Roberts Jr., writing for the court, narrowed the definition of what sort of conduct can serve as the basis of a corruption prosecution.
He said that only formal and concrete government actions counted. What Mr. McDonnell had done, by contrast, the chief justice wrote, was arrange meetings for and attend events with his benefactor.