It is not just that America’s citizenry has stabilized itself upon gridlock, so, too, has the American mindset. The base American mindset is spit 40— 60% right vs. center-left, with the primitive right, simply because it remains intellectually unadorned, being much more tightly bound to the negative half of its tribal instincts (xenophobia).
This means that even the slightest splintering of purpose on the more intellectually nuanced center-left will fatally undercut the seeming numerical advantage it holds. Sure the center-left and far left will come together in protest marches against the right once it has allowed the horse to escape the barn (because it voted for third party candidates and engaged in other defeatist strategies). The main difference between the better educated and more worldly center-left and Trump’s down home, rock hard following is not so much passion as focus.
No matter how badly focused are the Trumpsters on what is true, they remain fanatically focused on what they hate. Conversely the left center is enormously defused on what it likes and wants, a deadly political liability. While this has always been the case, the great difference now is that the right is mainly based in a single party, giving it leverage way beyond its days of old.