A couple of platitudes in U.S. politics:
"Never overestimate the intelligence of the voters."
"the pendulum swings both ways." The first got us where we are. But whenever the party in power goes to the extreme, it forces a move to the opposite.
The growth in registered Independents over the past several election cycles suggests how "fed up" many are with both parties. Independents will decide this election. Independents are more likely to vote for the candidate that most supports positions that are important to them.
I don't know the demographics of the Independant voter, but I'd wager that they are: more educated, earn more money, are fiscally conservative and socially moderate. Who they gonna vote for?