I think it was a joke.
Of course it was a joke but it’s clear that it’s intended to make him seem like a deplorable.
Agreed, he seemed like kind of a dick - his brother said he would bring a cigar with him to the casino even though he didn’t smoke- if someone lit up around him he would light the cigar and blow it in their direction. He was passive aggressive and liked to make people uncomfortable. I know a guy like that, he gets off on making people uncomfortable. A lot of loner types are like that.
Pretty sure the Trump wall comment was the same, he knew it would make people feel weird.