Polls of the contests on Super Tuesday had a weighted average error of 12.8 points, with 60 percent of them conducted mostly before Biden’s big South Carolina win and subsequent endorsements by onetime 2020 presidential contenders former South Bend, Indiana, Mayor Pete Buttigieg and Sen. Amy Klobuchar.
South Carolina polls had a weighted average error of 17.2 points (!), and 75 percent of them were conducted mostly before Rep. Jim Clyburn’s endorsement of Biden.
Polls of all other contests — Iowa, New Hampshire, Nevada and every post-Super Tuesday state — had a weighted average error of 7.1 points, which is quite good by historical standards for primary polls.
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[W]hen a poll shows a close race, your takeaway shouldn’t be, “This candidate leads by 1 point!” but rather, “This race is a toss-up.” Polls’ true utility isn’t in telling us who will win, but rather in roughly how close a race is — and, therefore, how confident we should be in the outcome.
From the article:
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