This sentiment had been building for decades. Between 1866 and 1906, six bribery cases were brought before the Senate. In the Western states, miners who achieved instant wealth sometimes aspired to higher office. In 1899, two rival mining company owners -- W.G. Conrad and William Clark --paid more than $1 million in bribes in hopes of obtaining a U.S. Senate seat representing Montana, according to Wendy Schiller, a political science professor at Brown University.The contest lasted through 17 ballots before a winner could be decided, and the two candidates had to pay up before each day's ballot to prevent their supporters from switching sides, she said.Clark eventually won, but the U.S. Senate refused to seat him and the spot was vacant for two years.