Illinois – Two new polls show Republican Mark Kirk is holding a slight lead over Democrat Alexi Giannoulias in the race for Illinois' U.S. Senate seat. However, both poll results are in the margin of error. A Mason-Dixon poll conducted for the Decatur Herald & Review and the St. Louis Post-Dispatch gives Kirk the backing of 43 percent of registered, likely voters to Giannoulias' 41 percent. A Chicago Tribune/WGN poll shows Kirk with a 44 to 41 percent advantage over Giannoulias. Four weeks ago, the Tribune/WGN poll showed Giannoulias held a two-point edge over Kirk, 38 to 36 percent.