Ezra Klein frames up the election well here:
This is the argument coursing through this election. Democrats believe America’s rising diversity, its increased emphasis on inclusion, is making it greater. Republicans have nominated a candidate who represents and channels the fears of that diversity, the sense of displacement — both real and imagined — that accompanies that inclusion.
Check out a different view from Peter Beinart:
But when Elizabeth Warren and Bernie Sanders took the stage later in the evening, the convention began to sound much more like the campaign Gore actually ran: the dark and angry, “people versus the powerful.” Warren said: “I’m worried that opportunity is slipping away for people who work hard and play by the rules.” Sanders talked about “the 40-year decline of our middle class” (40 years that include the presidencies of Bill Clinton and Barack Obama), called American inequality “grotesque,” and said America was moving “toward oligarchy.”