TALLAHASSEE, Fla. — Gov. Ron DeSantis signed a major rewrite of Florida’s elections law on Thursday, tightening rules around drop boxes and mail-in voting in the presidential battleground. Critics say the changes will make it harder for voters, particularly the elderly and people of color, to cast ballots. It’s the latest victory in the nationwide push by Republicans to restrict access to the polls, which party leaders say is necessary to deter fraud.