He won the popular vote in 2016 in States like Wisconsin that for months said he was 10-15% behind in the polls. It’s my interpretation that those polls were wrong but the majority of the media didn’t care. They just wanted to push a narrative that supporting Trump was a fringe minority in those States, rather than the true majority that it was.

This is not an accurate description of the magnitude of polling error in 2016 in WI, which was the state with the most significant polling error that year by a very large margin, see Table 2 "2016 final polling average versus actual results": https://centerforpolitics.org/crystalball/polling-error-in-2...

The final difference from polling in WI was 7%, other states had smaller polling errors. The fact is that 2016 was simply an extremely tight race in many states and difficult to forecast even with completely normal polling error bars.