These are polar opposite approaches to governing a population which is why there is such an inability to cooperate on policy and laws which will apply to the American people.
Republicans have moved further right than the Democrats have moved left which has resulted in the entire country moving a little further to the political right. The appeasement of fringe groups has resulted in a dangerous union based on special interests which should have little to do with proper governance. This has left the United States hopelessly gridlocked and unable to agree on even the most fundamental issues of public policy.
Now with a fake populist liar in the White House things have gotten worse in that those in most need of help from Democratic policies are voting against their own interests because they don't know better or are fed up of the status quo and wanted to stir the pot by electing a novice who promised change.
But even if you disregard the blip on the radar that is Trump, this stalemate between two opposing parties is perhaps doing doing irreparable damage to a republic teetering on the edge of self destruction.