Just as 2016, US presidential election might be closer than polls suggest

With less than two months until the US presidential election, Democratic nominee Joe Biden leads incumbent Donald Trump in the bulk of opinion polls.

But poll-based election forecasts have proved problematic before. The polls were widely maligned after the 2016 election because Trump won the election when the majority of the polling said he would not.

What went wrong with the polls in 2016? And is polling to be believed this time around, or like in 2016, are the polls substantially underestimating Trump’s support?

Swing states decide US presidential elections

US presidential elections are two-stage, state-by-state