So, the polling numbers are wrong because people are worried about a polling company random dialer being used to track people who answer a question in favor of Donald Trump (which i mean, seriously?) , but not so worried that they have signs and flags on their property where land records are public and can be searched online, and everyone on the planet has a phone that can take a picture of them at a rally.
That's the sum total of your post? I mean, your conclusion may correct, but still. Seems a weird way to get there.
Why are Trump supporters ashamed to say they are supporters you think? I don't see that much. Ashamed that they ate the entire dozen at Dunkin, I see that a lot these days. But I'm not bumping into many people unwilling to share their opinion on, well, anything.