Larry Sabato explains the likely results of November’s Senate elections:
The calculated takeaway is this: As of now, Democrats are clear underdogs in the two states where they want to play offense. They also are probably no better than 50-50 in any of the seven red states where they are defending seats, and drowning in a couple. A big enough wave could cut into the blue states, too, although probably not as deeply as Republicans fantasize. Put it all together, and the current forecast calls for a wave that’s more than a ripple but less than a tsunami – a four to eight-seat addition for the Republicans, with the higher end of the range being a shade likelier than the lower. For Harry Reid, that would be a big-enough splash.
For a real Republican wave to emerge they would need to do significantly better than that. Two things would both need to happen: the president’s support would need to collapse and Republicans would have to run completely error-free campaigns. Since I don’t believe that both of those things will happen, I think that the Democrats will hold the Senate.