US is the old democracy in the world. I live in brazil and there a bunch of reporters histeric people here assuming US will be a dictatorshio soon. Bitch, we where a dictatorship like 35 years ago, Time to worry about our own problems here.
It does seem very likely that the Republican Party will govern the US for decades to come, like Perón's party has governed Argentina in between the military dictatorships, or Chávez's party governs Venezuela.
Either you're a troll, governed by recency bias (i.e. today), or not very competent in US politics. If the Democrats could get their act together even just slightly, they should have won 2016 and this election as well. How? It's simple demographics:
More and more people move to cities -> cities are typically blue -> easy for dems to get elected.
There should be absolutely no reason democrats lose so often and yet due to their incompetent antics they lose far more than they should.