In every one of the past six presidential elections, Democrats have won states that add up to about 240 electoral votes — pretty close to the majority needed to win. Republicans have won about 103 electoral votes in each of the past six elections, so there’s a big hill to climb. Any GOP nominee has little room for error and would have to win all the big battleground states — Ohio, Florida, Virginia — or else find some blue states they can flip to red.
http://www.npr.org/2016/03/18/470911185/can-donald-trump-rewrite-the-electoral-map-for-the-gop
