Kathleen Kee, a home health nurse, stood at her kitchen counter, still dressed in scrubs, staring in disbelief at the voter information card from the Palm Beach County supervisor of elections. There, in the upper left corner spelled out in bold uppercase type, was her new polling location: The Islamic Center of Boca Raton. A mosque? Kee fumed to her husband, who agreed that a mosque was not an appropriate place to vote — not this year, not given the terror attacks exploding around the world, not in the immediate aftermath of the Orlando nightclub massacre, carried out by a...