I think people overrate the degree to which construction workers will vote for Trump. Many are conservative in terms of outlook but they also tend to be union members that vote on bread and butter issues. I actually would argue that on balance they'd lean Biden since non-white construction workers are overwhelmingly Democrat and a sizable minority of the white ones are as well and actually sort of strike me as Obama-Trump-Biden voters.
You could be right, but they seem to be overwhelmingly non-college educated males. A core Trump constituency. Which explains why people overestimate.
non-college educated males aren't a core Trump constituency, non-college educated white males are
