You do realise that gaining a majority is impossible with writing off rural (and urban, a lot of the swings in WV, OH are in semi-urban areas) hicks and I'm pretty sure suburban voters will swing against the Democrats with a Sanders presidency, allowing Democrats to be in the permanent minority.
2004: GWB won bigly and the GOP got 55 senate seats! Permanent Republican Majority!!!!!!!!!!!!!
2008: Obama won bigly and his party got 60 Senate Seats and 257 House Seats!!!! In 2010 the Dems can add OH, NH, MO, etc. to their Senate arsenal! Permanent Democratic Majority!!!!
2010: Welp, the house is Republican for life now and Obama is done in 2012!!!
2012: Republicans will never ever ever win the Presidency Again!!! Permanent Democratic Majority folks (once the house is no longer gerrymandered)!!!!!
2016: Well, well, well, if Donald Trump can win now, the Democratic Party should just go die in a hole somewhere. They'll never even win races for dog catcher. Permanent Republican Majority!!!!
2018: Democrats did okay, but they didn't win by enough, so....Permanent Republican Majority!!!
Certainly a departure from the usual trend, lol