1. The 2016 presidential and Senate target states are almost perfectly aligned.

With the exception of Virginia, every presidential battleground state could have a top-tier Senate race. Additionally, one of the most vulnerable Republican incumbent senators in the country is from Illinois — a safe Democratic state. In the 2012 presidential race the vast majority of money spent on general election television ads was targeted at these swing states.

In 2008 and 2012, Democrats ran superior grass-roots campaigns in these battleground states. Similar well-financed efforts in 2016 could prove decisive in determining control of the Senate.