Interesting post. And I agree that the poles are biased against Republican candidates. And there is no reason to not believe his Exit Polling Data.
But the anti-GOP bias cannot be caused by a reluctance of Republicans to answer pollsters. The reason: pollsters use models of the electorate. They have to have X Dems, Y GOP, Z Independents, ZZ Libertariians and ZZZ Other. Or something like that.
Its the models that hold the bias. They overstate the Dem proportion of the voting public so the Garbage In, Garbage Out Rule applies.
I think this going to be a bad year for the Pollsters. OTOH Im looking forward to reading what Nate Silver has to say Wednesday morning.
He's going to say the same thing he said in 2016 - we got the popular vote correct, but at the district and state level we didn't get the distribution correct - translation: In Red areas, they don't see the undertow...