That would be the clincher for me. 
I caught the end of Rush's show today where he talked about "the Wilder effect," which was exhibited when former Gov. Doug Wilder ran for re-election in Virginia. The exit polls of the voters showed Wilder winning in a landslide. The opposite happened. Rush went onto say that this was chalked up to voters not wanting to appear racist to the exit pollsters, thus opening themselves up to further cajoling and questions. So, the said that they had voted for Wilder, when in fact they had not. Hence, "the Wilder effect."
Rush went on to describe what Don Lemon of CNN had said on-air as being the
opposite of this--that there are a
lot of people who support Trump, but won't say so on camera for fear of being labeled as a racist. We'll see if "the Trump effect" comes into play. My guess is that Don Lemon wouldn't say this unless he felt that it could be substantial.