November 2, 2020: Final Forecast
The last eight polls in the RCP average for Pennsylvania have five showing Biden with a lead, and three showing Trump with a lead. The previous seventy polls showed a lead for Biden in all but three polls. This is the last minute tightening that is a huge positive signal for the Trump campaign. The RCP average for Pennsylvania has shrunk to Biden +2.5. In 2016, Trump beat the polls by 2.6%. Trump has been hitting the Keystone State hard over the past week, with large turnout for his rallies, and a heavy advertising blitz focusing on what a Biden/Harris administration would do to the energy sector. ElectoralMap.net is predicting a Trump win in Pennsylvania, with the strong possibility that an extended ballot counting period of days or weeks flips it to Joe Biden.

Although polls have tightened in Minnesota, Michigan, and Wisconsin, Biden still has a larger margin than the polling error in 2016 - so those states are staying in the Dem column in the forecast. Expect the races to be close, though. Likewise Arizona, Georgia, and North Carolina are breaking in Trump's favor in last minute polling - states that were probably Trump's all along.

We may have a fairly good barometer for this election: Florida and North Carolina returns could come in reasonably early, and if either of those states goes for Biden he will almost certainly win, if he takes both then it's basically over for Trump. This brings us to the topic of Florida. The latest polling data hints that Florida could be Trump's biggest vulnerability. The polls are not tightening in Florida in the same way they are in Pennsylvania. This is really bad news for Trump, as he's still about 0.7 points away from getting inside 2016's polling error. That RCP figure, however, doesn't weight the Trafalgar poll (October 29, Trump with a 3.1% lead) the same way ElectoralMap.net does - a much heavier weighting for 2016 accuracy. Over on the PredictIt prediction market, Trump has had a massive surge in Florida which started around October 19th. Although this site doesn't weight PredictIt heavily, the surge is big enough to move the Sunshine State into Trump's column. However, Florida could very well be every bit the showdown as it was in 2000.

The map is getting quite interesting
October 31, 2020
It looks like Biden has New Hampshire, Nevada, and all four Electoral Votes in Maine in the bag. On the flip side of the coin, Florida and Arizona polls have shifted in Trumps favor. If this election is anything like 2016, those five states can be moved out of the tossup category. Under these conditions, the map appears to favor Trump, as he's only 11 EVs away from a win, with four close states to make it happen. However, two of those states are only worth ten EVs. 269 is not a win, so he has to pick up two out of the four to secure a win with a buffer against faithless electors.

If Trump were to only pick up one of the ten pointers in this scenario, we'd end up with a 269/269 tie and an already messy election will get ten times worse. Faithless electors could throw the results one direction or the other. Even worse, an unexpected single EV flip in Maine or Nebraska (the two states that break out their EVs) could result in an exact 270 win. In that case, a single faithless elector could undermine a legitimate win in the election. If either Biden or Trump were to hit 270 exactly and then have it stolen from them by a faithless elector, massive unrest is almost a guarantee.

Neither candidate crossing the 270 threshold is essentially the same as a tie. The decision for President would then go to the newly elected House, where each state's delegation casts one vote - majority required to win. The newly seated Senate would pick the Vice President. But the Senate stands a great chance of ending up tied as well. Yeah, huge mess. Pretty much the only person in the country who could be pulling for that kind of disaster is Nancy Pelosi, who becomes the President on Jan. 20th if the Congress hasn't settled on a winner.

No, the polls were not mostly right in 2016.
October 15, 2020
There's a common refrain you've heard since the 2016 election, that the polls that year were actually mostly right. It's not true, and if you pay close attention to what is being written, even by reputable sources, you can pick apart the bad analysis. Some deflect with stories of down-ballot accuracy. Some insist the polls were accurate when taken, and blame the error on late-deciders. Most trying to make the case that the polls were good conflate state-by-state polling with nationwide polling, and once they've blurred the lines, you'll see the two used almost interchangeably. Although there was national polling that predicted the outcome of the popular vote quite nicely, it's irrelevant. The state-by-state polling was a disaster - and that's all that counts.

The United States does not hold a nationwide vote for President. Rather, the outcome of the Presidential race is determined by the Electoral College, which is determined by the individual elections in each state and D.C.. In 49 out 51 of these elections it's winner-take-all. This changes the strategy for an overall win, and it changes the way we try to predict that win. You can win the national popular vote and still lose the election, so we must forecast most of the individual states correctly. A good forecast for the national popular vote makes for an interesting piece of trivia, and nothing more. To correctly predict who will walk away with the Presidency, you need to have a good idea of how the vote will land state-by-state. Bad polling in just a handful of states can ruin the entire forecast. Missing key states is missing the election. Bad polling in a few key states is bad polling in toto. The pollsters know this, and the forecasters who rely on poll numbers know this too, but very few will admit how bad it was in 2016. The site you're reading right now missed 2016. FiveThirtyEight did too, by substantially more electoral votes. They, however, are hesitant to call the polling bad.

Not only did 2016's state-by-state polling miss critical states, it missed them all in favor of Clinton. In fact, virtually all of the closely watched swing states had polling error in favor of Clinton. The error in Wisconsin was absolutely terrible, being off by over 7%. Iowa was just as bad at 6.5% Pennsylvania, Michigan and Ohio all had error in Clinton's favor between 3% and 5%. North Carolina clocked in just under 3% error. These numbers are not just outside a reasonable margin of error, they are horrendously outside - and horrendous in nature. One of the primary benefits of poll-aggregation, not just for the overall election but for each individual state's polls, is that biases and errors tend to cancel each other out. However, when every single miss is in one direction, the aggregation is going to be garbage as well.

State	2016 RCP avg	2016 Actual	Error/Bias	2020 RCP avg
Wisconsin	Clinton +6.5	Trump +0.8	Clinton +7.3	Biden +6.3
Iowa	Trump +3.0	Trump +9.5	Clinton +6.5	Biden +1.2
Ohio	Trump +3.5	Trump +8.0	Clinton +4.5	Biden +0.6
Michigan	Clinton +3.4	Trump +0.2	Clinton +3.6	Biden +7.2
Pennsylvania	Clinton +1.9	Trump +1.1	Clinton +3.0	Biden +6.5
North Carolina	Trump +1.0	Trump +3.7	Clinton +2.7	Biden +3.3
Florida	Trump +0.2	Trump +1.1	Clinton +0.9	Biden +2.7
Georgia	Trump +4.8	Trump +5.2	Clinton +0.4	Biden +0.4
New Hampshire	Clinton +0.6	Clinton +0.3	Clinton +0.3	Biden +11.0
Arizona	Trump +4.0	Trump +3.5	Trump +0.5	Biden +3.5

So why are forecasters hesitant to admit how bad the polling was in 2016? All election models are simple garbage-in-garbage-out propositions, and an admission that the polls can be garbage is an admission that the forecast might very well be garbage too. The bottom line is that they rely financially on you believing that the next forecast they make will be accurate. Their bread and butter is people believing in the predictive power of their models, and if you don't have faith in their raw data then you might not tune in for their interpretation of it. That's the generous take. The not-so-generous take would be that they know that there is psychology in play, and that their forecasting doesn't just predict the vote - it can move it. When your team is hopelessly behind, you leave the stadium to beat traffic. The Daily Kos just told its left-wing readers that "people are motivated by winning, not losing."How many Trump voters stayed home in Wisconsin that night because Hillary had a six point lead and an 84% chance of winning?

The million dollar question, of course, is "will the polling be more accurate in 2020?" Shown in the rightmost column is the current polling for the same set of critical swing states. If the pollsters learned their lesson and corrected the flaws in their samples and methods, then the only interpretation is that Trump will unequivocally lose the election. Even if you subtract out 2016's bias from the current figures, Trump is facing an uphill battle with little hope. There is, however, one more possibility: that the polling now is even worse than it was in 2016. In that case, it's Biden that is in for a rough night. Could this possibly be the case? The fact that most forecasters and prediction markets are calling it a 70/30 race right now tells you that they either don't believe these polls, or believe that the polls are about to tighten substantially in the coming weeks.

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