The Washington Post provides a good overview of the race for control of the Senate. Click through for the interactive map.
Democrats have a good chance to take control of the Senate just two years after losing it. A friendly map with seven Republican-held seats in states President Obama won has opened the door, and now Republicans are hoping Donald Trump doesn’t drag them down in the many tough states they have to defend. These ratings are calculated based on polls, the history of how states have voted, conversations with smart political analysts and where outside groups are focusing their campaign spending. Toss-up states are close to 50-50, while “lean” states favor one candidate or another but are still potentially competitive in 2016.