The Democratic pollsters, who typically compete against each other for business, acknowledge that Trump was able to activate large numbers of voters who had turned out less reliably in the past. Looking at one state where the polls were off — Iowa, where Trump beat Biden handily and what had been seen as a toss-up Senate race went decisively for incumbent GOP Sen. Joni Ernst — Republicans classified as “low-propensity voters” turned out at four times the rate of Democrats in that category, according to the Democratic memo. “This turnout error was clearly one factor in polling being off across the board, but especially in deeply Republican areas,” the memo reads. “It also meant, at least in some places, we again underestimated relative turnout among rural and white non-college voters, who are overrepresented among low propensity Republicans.” But sky-high turnout for Trump among irregular voters only explains a small slice of the problem, the pollsters concluded. Even if the polls conducted last year were properly adjusted for future turnout, they still would have been biased toward Democrats. The memo floats at least three possible causes: late movement toward Trump and Republican candidates that polls conducted in the run-up to the election failed to catch, the Covid pandemic causing people who stayed home to answer the phone at a greater rate than those who did not follow restrictions, and the decline of social trust and faith in institutions.