I like like the math behind this but others might just know his conclusions. Based on analysis of previous elections and the electoral maps out there, Republicans need to pick up 8 or 9 Senate seats in 2014 in order to still hold majority after 2016. It will take wins in the House, Senate and Presidency to even try to turn this ship around. (This should have happened in 2012!)http://www.realclearpolitics.com/articles/2014/02/20/computing_democrats_risk_of_losing_the_senate_121640.html
Over the past two cycles, the president’s job approval has explained 58 percent of the variance in competitive Senate races in any given state.
...unless 2016 turned out to be a good Republican year overall, that Republicans would probably have to win 53 or 54 seats in 2014 to feel good about their chances of holding the Senate two years later.
At Obama’s current 44 percent approval rating, we’d expect Democrats to lose somewhere between nine and 13 seats.
If we run our simulations around [his average rating 48.3 percent over his presidency], we get the following overall distribution of outcomes:http://www.realclearpolitics.com/images/wysiwyg_images/chart3-2-20.gif
(The only way Obama recovers from where he is today back to his Presidency average is if Republicans either take off the pressure or if they self-implode. Both scenarios are possible.)