It also destroyed the coal mining industry but our President refuses to acknowledge this and is trying to prop the industry up by weakening environmental regulations.
Gas was hurting the coal industry long before fracking came along. Coal miners were looking for support from politicians who were just ignoring them. So he gave them hope, just like Obama gave his supporters hope when he ran. While Trump couldn;t reverse the trend, he still helped the coal industry where he could. That's better than the Democrats would have done. Who would you vote for if you lived in a coal mining town? The fact is Trump got millions of crossover votes from traditional working class Democrats. They see him a one of them, not some guy living up in the clouds despite the fact he's a billionaire. He worked hard, took a lot of crap, still does, and knows how to give it back. Coal miners identify with people like that, not with the Hillarys or Warrens or Buttigiegs.
Biden is a better match for them, but I don't think he's going to win the nomination. As long as the Democrats focus on impeachment, the more they put a target on Biden's back as being just another insider who used his position to get his son a job. Trump can get away with that because that's who he is. But Biden claims to be different when he isn't.