I find this unlikely considering the unusually high number of red States that Democrats had to defend in 2014. The most they could lose is two seats to maintain control, lose another one and VP Biden would be the tie breaking vote. Lose only four and the GOP is in power, as in OTL. That said, if the Democrats somehow defied expectations and maintained control, it probably wouldn't change anything. McConnell and the GOP would still use Congressional procedure to obstruction everything Obama tries to do. Garland could get a Senate hearing in 2016, but the GOP will just filibuster his nomination. So two more years of gridlock and obstruction. Trump most likely is still elected POTUS.