Political prognostication is hardly a science, but a number of analysts have looked closely at the 34 Senate seats up this year and identified those where the races will likely be very competitive. Drawing on forecasts by Sabato’s Crystal Ball, Roll Call, National Journal, Charles Cook Report, and the Rothenberg/Gonzalez Political Report, there appear to be between nine key battleground states where a small number of votes could mean the difference between a Democratic or Republican victory in November. In two other states, Republican incumbents could be in trouble but are currently favored to win re-election. And in Indiana, the Republican incumbent is retiring, which could result in a competitive race.
Among the nine most competitive states, seven Senate seats are currently held by Republicans. In one of them, incumbent Marco Rubio is running for president and not seeking to keep his Senate seat. Two of the battleground states are now held by Democrats. In Colorado, Democratic incumbent Michael Bennett is seeking re-election. In Nevada, Democrat Harry Reid is retiring, so the seat is wide open.