One of the bigger differences in polling between the 2016 and 2020 elections is that fewer voters appear to be supporting third-party candidates in either the Green Party or the Libertarian Party.
And as recent polling from NBC News indicates, voters who supported third-party candidates such as Green Party candidate Jill Stein and Libertarian Party candidate Gary Johnson four years ago are now telling pollsters that they're backing Democratic nominee Joe Biden over President Donald Trump by roughly a two-to-one margin this year.
"Forty-seven percent say they’re voting for Biden, 20 percent are supporting Trump, and 33 percent are unsure or say they’re backing another candidate," NBC News reports.
This is significant, according to NBC, because "in 2016, Trump won Michigan by 10,704 votes, while the combined Johnson/Stein vote was 223,599" -- meaning that Biden would be on track to win Michigan this year if he holds onto his current margin among Stein-Johnson voters.
Looking at the numbers, a similar story emerges in Wisconsin and Pennsylvania: If Biden wins over 2016 third-party voters at the rate current polls suggest, he would win both of those states.
"These Johnson/Stein voters are significant," NBC News concludes. "And right now in 2020, they’re more likely to be Biden voters than Trump voters."