A lot of anti-establishmentism is uninformed (that's not a snide remark, uninformed voters are a vital aspect of keeping politicians in line) and this forum is better informed than most.
Also a lot of people here view politics either as an amusing bloodsport or as a clinical exercice of study.
What Crabcake said.
Also, to the extent that forumites are disadvantaged, they are disadvantaged in ways that typically don't lead up to supporting Trump. How many here haven't been to or plan on going to university? Who's been laid off from a manufacturing position?