Claim: Republican nominee Mark Kirk won with an overwhelming margin over Democratic bet Alexi Giannoulias  at the 2010 United States Senate elections in Illinois and as of 2020, he is the last Republican to succeed at the US Senate elections in Illinois.
Evidence: Kirk defeated Giannoulias in the election for the full six-year term, getting 48% to Giannoulias's 46%. 
Republican Mark Kirk 48.0 46.4 Alexi Giannoulias Democratic