If presidential performance was the only thing that mattered in determining the outcome of a U.S. Senate race, then perhaps first-term Republican Sen. Mark Kirk should be polishing his resume. Fortunately for Kirk, presidential performance isn’t the only factor, but it does provide a good indication of challenge he faces in his bid for a second term. No Republican presidential candidate has carried Illinois since 1988 when then-Republican Vice President George H.W. Bush defeated Democratic presidential nominee Michael Dukakis, 51 percent to 49 percent. In 2008, favorite son Barack Obama took 62 percent of the vote to 37 percent for GOP nominee John McCain. Obama carried the state again in 2012 by a slightly lower 17-point margin. That 17 points is important, though, as it makes Kirk the Republican incumbent who must run in the bluest state this cycle. In 2014, four Democratic incumbents were in Kirk’s shoes; they had to run for re-election in states that Republican presidential nominee Mitt Romney carried. Democratic Sen. Mark Pryor of Arkansas had to run in the reddest state last cycle as Romney

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