Starting off the piece we get the following: "I can’t believe the poll. I’m a lifelong Republican. Most but not all of my friends are Republicans, and I don’t know one of them who supports Trump — not one."  Hmm. No one I knew voted for Reagan. He could not have been elected.
But seriously. My suspicion is that in general, it is more common for conservative thinking people to look around their limited sample size and conclude much more of the populace is in agreement with their ideas than is true. 
I am not saying liberals are immune. I saw many comments from very surprised Sanders supporters who saw large crowds and thought he'd win New York. But it is just a suspicion (from my own limited sample), that the more absolutist thinking of Conservatives leads to this effect, whereas the more relativist thinking of Libs means they less often are confident the populace agrees. Comments?
Finally, foreign born recently single citizenship Cruz is a strict constitutional constructionist?