An ongoing legal battle playing out in Fort Lauderdale federal court over the Democratic National Committee’s presidential nominating process has devolved into accusations of harassment and intimidation conducted by unknown political operatives. Last month, an attorney representing 150 Democratic voters in a little-noticed class action lawsuit against the DNC and its former chairwoman, U.S. Rep. Debbie Wasserman Schultz, sought court-ordered security guards for himself, his clients, and his co-counsels and their employees following a string of bizarre incidents in June, including strange phone calls and emails by individuals disguising their voices and a mysterious break-in at the home of one...