In the final weeks before Election Day, Republican groups have filed lawsuits in the swing states of Michigan, North Carolina and Pennsylvania that challenge the validity of ballots cast by U.S. citizens living abroad, including members of the U.S. military.
I’m guessing the ones they are targeting are the ones who are registered democrats, since that information is easily obtainable.
Also guessing that republicans outnumber democrats in the military ~3.5:1