In recent history, Republicans had dominated U.S. Senate elections in Illinois, with only Republicans having been elected to the U.S. Senate from Illinois since popular elections were adopted after the 1912 and 1913 United States Senate elections. At the time, Lewis, in 1913, was the last Democrat the state had elected to the U.S. Senate. Some saw the Republican primary for U.S. senate as tantamount to election in Illinois.
