Between 1901 and 1907, a broad coalition of Protestant churches sought to expel newly elected Reed Smoot from the Senate, arguing that as an apostle in the Church of Jesus Christ of Latter-day Saints, Smoot was a lawbreaker and therefore unfit to be a lawmaker. The resulting Senate investigative hearing featured testimony on every peculiarity of Mormonism, especially its polygamous family structure. The Smoot hearing ultimately mediated a compromise between Progressive Era Protestantism and Mormonism and resolved the nation's long-standing "Mormon Problem." On a broader scale, Kathleen Flake...