NBC News - The unprecedented combination of Covid-19 and sky-high interest in the presidential race have made 2020 an especially challenging one for election administrators.
But it could also make drawing conclusions from the initial results reported Tuesday night particularly hazardous.
It's likely that in Sun Belt battlegrounds such as Florida, North Carolina and Texas, the first totals to be reported will be huge tranches of mail and early in-person ballots that break heavily for Joe Biden, creating a "blue mirage" in the early tallies that could be erased once Trump-friendly in-person Election Day votes are tabulated.
But the opposite could be true in northern battlegrounds such as Michigan, Pennsylvania and Wisconsin, where officials are not permitted to begin processing mail ballots until the day of the election (or, in Michigan's case, the day before). In those states, a "red mirage" of Trump-heavy Election Day votes could linger until larger metro counties report huge tranches of early ballots later in the evening.
The lesson: it will be easier than ever for initial vote tallies to lead untrained eyes astray. So patience is essential for the media and the public, and it's critical to wait for experienced, statistically driven network decision desks to make projections.
Nearly 100 million voters have cast ballots in advance of Election Day, almost double the 57.2 million the U.S. Election Assistance Commission estimates were cast early in 2016. And it's possible that between 150 million and 160 million voters will ultimately cast ballots this year, up from 137.1 million four years ago.
All year, polls have depicted a massive, unprecedented partisan divide in how voters plan on casting their ballots — Democrats early, Republicans on Election Day. And there's no doubt President Donald Trump's rhetorical fusillades against expanded mail voting have played a big role in driving voters into different camps.
According to the final NBC/Wall Street Journal national survey, Biden led 61 percent to 35 percent among the 68 percent of voters who said they had already voted or planned to vote early. But Trump led 61 percent to 32 percent among the 28 percent of voters who said they planned to vote Tuesday.
A little-covered June special election for a congressional seat in the Buffalo, New York, area offered a preview of what a "red mirage" could look like. When counties reported results from Election Day polling places that night, Republican Chris Jacobs led Democrat Nate McMurray 68 percent to 30 percent. But when heavily Democratic mail ballots were tabulated in the days after, Jacobs' lead dwindled, and he won with just 51 percent of the vote.
A similar pattern could play out on a much larger scale in next-door Pennsylvania, which has emerged as perhaps both campaigns' most critical state in the final stretch. At least seven counties have said they will not begin counting mail-in ballots until Wednesday morning, and many large counties — including Philadelphia and Pittsburgh's Allegheny — say they may report only partial counts of mail-in ballots on Tuesday night.
There are very few counties in battleground states expected to report nearly all their votes up front, but the one exception could be Sumter County, Florida, home of The Villages retirement mecca, which could offer a rare early clue.
Already, 83,139 of Sumter's 105,612 registered voters have cast early ballots, by far the highest turnout rate in the state.
Because Florida law permits counties to begin processing early ballots 22 days before Election Day, Sumter is expected to report the results of those 83,139 ballots quickly after polls close Tuesday — and that could amount to between 85 and 90 percent of the entire vote in the county. In 2016, Trump won Sumter 68 percent to 29 percent en route to winning by one point statewide, and he likely needs to win the county by at least two-to-one to take Florida again.
But if he's only winning the first large batch of Sumter's votes with 64 percent or less, it could signal a potentially catastrophic loss of support among seniors since 2016 and bode poorly for his chances of winning Florida, and a second term.
Pretty much everywhere else, however, the partisan gap between the early vote and the Election Day vote is likely to vary so much that it will be extremely hazardous to read into the results before individual counties report that they have completed counting.
The bottom line: Beware any pundit, online or on-air, who tells you an early lead in any given state's vote tally is fantastic news for one candidate or the other. The uncharted nature of this election means they could be looking at a red or blue "mirage."