In addition, a federal lawsuit filed last week by a group of House Republicans in Pennsylvania argues that voter ID requirements are not stringent enough to prevent fraud in overseas ballots. The suit alleges that Pennsylvania Secretary of State Al Schmidt, a Republican, has instructed officials to allow U.S. citizens voting overseas to be exempted from voter ID requirements.

Pennsylvania, Michigan and North Carolina are three states that do not require overseas citizens first provide identification to be sent a ballot, a fact that former President Donald Trump has baselessly claimed would allow Democrats to steal the election. Those voting overseas have previously registered to vote in their last confirmed state of residency, where they needed to present ID and provide their signature.

Patrick Gannon, a spokesperson for North Carolina's bipartisan State Board of Elections, told NBC News that the current rules have been in place for 13 years. A change, he said, would prevent military families and other citizens from casting a vote. If the GOP had an issue with this, he said, the party should have challenged the rules for voter eligibility "well before an election, not after votes have already been cast."

Michigan and Pennsylvania's top election officials have accused Republicans of trying to disenfranchise voters and spread mistrust about U.S. elections.

The lawsuit in Pennsylvania was "nothing more than an attempt to confuse and frighten people ahead of an important election," a spokesperson for the Pennsylvania Department of State said. The legal action is merely "a continuation of the unfounded litigation in state and federal court filed in 2020 in an effort to sow confusion and ultimately to throw out the votes of millions of Pennsylvanians and overturn the results of that legitimate election."