Coattails and Correlation By Geoffrey Skelley
Few political observers will be surprised that the correlation between presidential and Senate results has been increasing over the last few presidential election cycles. That is, during a presidential election year, the Senate race in state A has increasingly tended to have a similar outcome to the presidential result in state A. Other analysts have noted the growing relationship between the two variables, such as National Journal, which produced a great infographic examining the 2000 to 2012 elections.