Would people who spoke out negatively potentially receive reprisals, even if not explicitly so? I'd imagine they'd lose opportunities, have their career affected and be treated differently.

In that case, I wouldn't be so sure about your numbers because people will lie about positions if they think they'll be negatively impacted by a "wrong" answer.

This is one of the reasons why the 2016 election polls were so wrong. When polled, a certain number of Trump supporters would lie and say they supported Clinton.