Hansi Liu Wang

Michigan is one of more than three dozen states that allow voting by U.S.

citizens who are born abroad and have never lived in the United States.

That's sometimes because their U.S.

citizen parents or legal guardians served abroad in the U.S.

military.

A Michigan law allows overseas non-resident voters to register if a parent or spouse last lived in the state before leaving the country.

The Republican National Committee, however, is arguing in court that Michigan's longstanding law violates the state's constitution.

The RNC claims counting those voters' ballots will disproportionately harm Republican candidates.

RNC filed a similar lawsuit in Arizona.

Republican efforts to restrict voting by U.S.

citizens living abroad began last year, with last-minute lawsuits challenging ballots in Michigan and other swing states.

Data shows this voting population is becoming less military and more civilian.

Anzi Luong, NPR News.