Forget the “shy Trump voter” narrative. Before the election, pollsters were worried that perhaps some Trump voters surveyed were simply too embarrassed to tell people that they were voting for him.

The real problem is even worse. Virtually every poll did not survey enough Trump supporters, period — meaning there’s a huge sampling error the industry needs to reckon with.

“We’ve been struggling with this issue and we keep trying to fix it and it’s not totally working,” said one worried pollster who did not want to be named for fear of ruining his industry.

It’s called “non response,” meaning pollsters are not getting enough Trump voters to even participate in a survey and answer questions.

This isn’t just a phone call survey problem. It’s in online surveys and text surveys, too.

“The major problem, the fundamental issue in the polling industry is declining response rate,” said Jon Cohen, chief research officer at SurveyMonkey.