FORT LAUDERDALE, Fla. — President Donald Trump, the nation’s most outspoken foe of mail voting, has returned his mail ballot for Tuesday’s Florida primary to the Palm Beach County elections office.The ballots for Trump and first lady Melania Trump were returned Monday.Also Monday, Trump continued his assault on the way mail voting operates. In a tweet, he criticized the use of drop boxes for mail ballots. That practice was expanded in Florida under changes signed into law by Gov. Ron DeSantis.Just two weeks ago, Trump praised Florida’s system of early voting, and DeSantis’ leadership.On Monday…