Article I, section 5, of the United States Constitution gives each house of Congress power to judge the elections, returns, and qualifications of its members, and to punish members for "disorderly behavior." Between 1793 and 1990, more than 200 senators faced challenges to their credentials based on their qualifications for office and alleged irregularities in their elections; or discipline for offenses ranging from public corruption, to giving aid and comfort to the Confederacy, to bringing dishonor upon the Senate in myriad other ways, or for pure political spite. As researched and written by staff of the Congressional Research Service, these are their stories. The arc of the book, each case told in chronological order, traces not only the tenor and politics of the times, but the evolution of the Senate's own thinking about what it means to be a United States Senator.