Shortly before the first 2016 presidential nominating contest in Iowa on February 1, critics, reporters, political operatives and maybe even a few curious fans will cram into a movie theater in Park City, Utah. Debuting at the Sundance Film Festival is “Weiner,” a documentary about the former congressman Anthony Weiner, who resigned following a 2011 sexting scandal, but reemerged as a candidate during a brief and calamitous run for mayor of New York City in 2013.
