The triangles on the right side of each plot are the actual election outcomes, and the little arrows on each graph show the dates of the Democratic and Republican conventions in each year. As you can see, polls this early are in many cases not even close to the outcome.
I’m sure that Dr. Tyson means well, and I’m a big fan of Nova, but, really, he should talk with some political scientists before glibly writing about politics and concluding, “The political analysts need to take it from here.” We’ve taken it pretty far already, dude! Tyson has every right to speculate about politics–I wouldn’t claim that you need some sort of political science affiliation as a “union card” to do political science research–but it would make sense to ask around a bit, right? I mean, if a couple of political scientists wrote a paper on astrophysics in a journal called Mathematical and Computer Modeling . . . well, before trumpeting it in the New York Times I’d first go up to the 10th floor and ask my friend David, the astronomer, whether it’s for real.