By Josh Chang
If the current polls in every state in 2020 are off by exactly the same amount and in the same direction as they were in 2016, Joe Biden would still win the electoral college 319 to 219.
So although the vast majority of pollsters and modelers incorrectly predicted a Hillary Clinton win, Biden’s lead as of late is far greater and able to comfortably absorb a 2016-esque error. If every single undecided voter in current polls voted for President Trump, Biden would still win, a threshold Clinton never came close to crossing.
Trump does have a chance of re-election, but it is narrow at best. A Trump win would require both a rapid tightening of the race with less than three weeks left and a gigantic polling error in his direction, both of which seem improbable.
There is also no evidence to suggest there will be a systemic polling bias underestimating Republicans this time around, as systemic bias is variable and unpredictable. National polls underestimated Republicans in 2004, Democrats in 2008, Democrats again in 2012, and Republicans in 2016.
The only somewhat successful predictor of polling bias in presidential elections is the bias in the preceding midterm elections. For example, polling in the 2014 midterms significantly underestimated Republicans, foreshadowing the same result in 2016. In the 2018 midterm polls, there was hardly any systemic bias, as pollsters largely corrected for their oversampling of college-educated voters, the cause of most of the systemic bias in 2016.
It is reasonable to ask why Biden is in such a solid position, and it is really quite simple. Donald Trump barely eked out a victory in 2016 by narrowly winning in a few key states, while still losing the popular vote by more than 2 points. The national environment now is much less favorable to Trump and Republicans in general due to the pandemic and the resulting economic deterioration. Naturally, you would expect an incumbent president in such unfavorable conditions to do at least slightly worse than his first election. With Trump’s slim margins in 2016, that would mean a Biden win.
