When is the last time we did have a president for all Americans? Kennedy?
Reagan, and kind of, Clinton. In the context they won broad majorities from the electorate and were considered more than just a Democratic or Republican president. There wasn't a region in the country they weren't competitive in (Clinton less than Reagan but still).
W. is when partisan identity began to really subsume everything else and Americans began to self sort and divide into factional loyalties.
This is why Kasich or Sanders each would've been particularly formidable had they been nominees. They were seen as more than a party label.
That's one way of saying that neither of them would have been the least popular candidate (in the history of modern polling) that their party nominated.
Poll
