But it's also the case that more turnout is generally seen to benefit Democrats, given that the factors that indicate a high-frequency voter -- age and income in particular -- correlate to more Republican voters. Get those less-frequent voters to the polls, and one would expect Democrats to benefit.
While early voting was underway, we saw reports from several states that turnout numbers were exceeding 2012 levels. (2012 was the exception to the rule in the first paragraph; turnout was down from 2008.) Now, with voters casting ballots on Election Day itself, there are reports that vote totals in two critical states, Pennsylvania and Florida, have exceeded or will exceed past turnout numbers.
PA official: Voter turnout today could exceed 80%. Would be highest total since Bill Clinton vs George HW Bush in 1992 (83%)— Ken Rice (@kenricekdka) November 8, 2016
With that in mind, we put together a little tool allowing you to track past turnout in the 12 closest states. This data is from the essential United States Election Project, and uses two very specific numbers. The first is that the pool of possible voters is the voting-eligible population, a larger group of people than simply those who are eligible to vote. In other words, this isn't an assessment of how many registered voters cast ballots, it's a measure of how many eligible citizens did. The number of ballots we use below is the number cast for the highest office on the ballot. In presidential election years, that's obviously the presidency.
It's those columns that you'll want to keep an eye on as results come in. Those are the ballots cast in the election, and it's the number that turnout records will need to beat.
Donald Trump's campaign will argue that spiking turnout is a sign they're doing well. After all, Trump's argued that he'll pull infrequent voters to the polls after being inspired by his candidacy. It's a reminder that big statewide turnout doesn't necessarily tell us who all those voters are voting for.