The Supreme Court has formally rejected several appeals from Republicans and former President Donald Trump over contested 2020 voting rules in key battleground states.

The court declined to take up a challenge to Pennsylvania's mail ballot deadline extension that became the fixation of Republican attempts to overturn results in that state. The justices also turned away a case out of Georgia, brought by Trump ally Lin Wood, over mail-in ballot requirements.

Justice Clarence Thomas, also dissenting from the decision in the Pennsylvania cases, wrote, the "decision to rewrite the rules seems to have affected too few ballots to change the outcome of any federal election. But that may not be the case in the future."

"These cases provide us with an ideal opportunity to address just what authority nonlegislative officials have to set election rules, and to do so well before the next election cycle. The refusal to do so is inexplicable," Thomas wrote.