2016 is a good year for the Dems to retake it back considering all the 2010 seats up for re-election.
That's likely exaggerated.
There are states that will be in play, but it's not like 2014 where Democrats are defending several seats in states Obama lost by 13.5 points or more (Alaska, Arkansas, Lousiana, Montana, South Dakota and West Virginia)
Mark Kirk is the only Senator in a really liberal state.
Florida, Ohio, New Hampshire and Pennylvania are likely to be competitive, but these are essentially purple states. Romney's seven point loss in Wisconsin doesn't suggest it's a state where Republicans need not apply.