Reconciliation was Lincoln's blunder, but we can't pin all the blame on him. The fact of the matter is the vast majority of the electorate has been purposefully dumbed down and lulled into a state of learned helplessness, while those who do manage to stay engaged are drawn into endless political culture wars that keep us divided down predictable party lines.
There are issues out there that 80-90% of Americans agree on, it's just that no candidate can ever make a platform out of those popular ideas without getting dragged down into the mud of divisive rhetoric so that people can easily place them into a neat little box that predetermines if they hate them or not without thinking too much.