I love the statistics lessons coming out of the Upshot, in the context of the upcoming election. In their most recent, Nate Cohn goes into varying statistical weights and how just one man can unknowingly shift the polls.
Our Trump-supporting friend in Illinois is a surprisingly big part of the reason. In some polls, he’s weighted as much as 30 times more than the average respondent, and as much as 300 times more than the least-weighted respondent.
Alone, he has been enough to put Mr. Trump in double digits of support among black voters. He can improve Mr. Trump’s margin by 1 point in the survey, even though he is one of around 3,000 panelists.
He also put Hillary Clinton ahead recently, because he wasn’t in the sample.