A lawyer for U.S. Sen. Bill Nelson's re-election campaign is suing Florida Secretary of State Ken Detzner.
The lawsuit filed Monday morning in federal court claims that the state is disenfranchising voters by not accepting mail-in ballots received after Election Day.
"No Floridian should have their rightful vote denied because of mail/post office delays," Marc Elias, an attorney representing Nelson and the Democratic National Committee, said on Twitter.
"We are suing to protect these ballots."
According to the lawsuit, nearly 3.5 million Florida voters requested to vote by mail, but as of Thursday -- two days after the general election -- "a staggering 874,818 of those VBM ballots has not yet been counted as returned."