By Jon Keller

BOSTON (CBS) – The polls say it’s all but certain Joe Biden wins a relatively decisive victory Tuesday night.

Should you believe them?

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Many of us still have a hangover from 2016, when a range of polls mistakenly forecast a narrow win for Hillary Clinton. But the truth is, those infamous 2016 polls weren’t far off at all.

As The Hill newspaper noted, national polling was right on the money – the 13 national surveys taken in the final days had Clinton ahead by an average of 3.1 points, and she won by 2.1 points. The problem was with polls in key swing states that missed late Trump gains.

But again, they didn’t miss by much: “In Florida, the largest of the swing states, the average of the final three polls had Trump ahead by three-tenths of a point. He won the state by 1.2 points. Ohio’s last poll gave Trump a 7-point lead, and he carried it by 8.1 points. The average of the three final polls in Pennsylvania had Clinton leading by a single point and the last poll taken had Trump ahead by a point. He won the state by seven-tenths of a point.” (Polling in Wisconsin, a “blue wall” state that stunned the Democrats by going for Trump, was further off.)

Since then, legitimate pollsters have corrected flaws in their modeling that resulted in underestimating Trump support, such as weighting for educational background. But the main reason why the polls are likely to hold up Tuesday is the striking consistency of how they’ve measured public support for Trump over the past four years and his performance against Biden in 2020.

As Massachusetts-based political analyst Bill Scher notes in a must-read Real Clear Politics (RCP) column Monday morning, “Trump has the unique distinction of never holding an approval number higher than 47.3% (forget about 50%) and almost never earning an approval number higher than his disapproval rating. (Trump was above water by just 0.1 points for one day, the very first day RCP began tracking his job approval: Jan. 27, 2017.)”

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Let’s go back to March 10, the day before the NBA suspended the season after COVID-19 infiltrated its ranks and an early moment when the virus became real to many Americans. The average of three March polls published on or before that date – a time of economic prosperity – had Biden up by about eight points – almost exactly where they have him today.

Scher again: “Trump has been weighed down by [his historically weak approval] numbers despite a growing economy for much of his presidency. The discrepancy between his poll numbers and economic numbers strongly suggests that most Americans have been so repulsed by his divisive, self-serving and just plain mean behavior that they didn’t care how fat their wallets were getting. They just want him gone.”

The president’s catastrophic mishandling of the pandemic – up to and including his jaw-dropping quip Sunday night that he’s poised to fire the nation’s top infectious-disease expert after the election – surely hasn’t helped his standing. But the cake was baked long before that.

Think of polls as a meat thermometer. They can take the temperature of your pork loin, but only if you insert it in the proper place.

Unlike 2016, the body of data has been so consistent for so long that it’s hard to believe the final polls are missing something.

However, as Ronald Reagan said of arms agreements with the Soviets, “trust but verify.”

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Watch the actual results come in on WBZ-TV via CBS News all night Tuesday, but also keep a device tuned to CBSN Boston starting at 8 p.m. for live, local results and analysis from Congressman Joe Kennedy, 2018 GOP Senate nominee Geoff Diehl, and yours truly.

Jon Keller