Because dey be racis!
I think part of it is also, because the Democrats are the party of every left wing cause, every wacko idea, the party of political correctness, the party of public assistance...........
Working class people go to work every day. What does the Democrat party have to offer such people? The Democrat party pushes global warming, homosexual marriage, affirmative action/minorities having special rights, illegal aliens having special rights, this bizarre business about “transgendered” bathrooms and all those related issues.
It’s as if every bizarre cause in the world has found its political home in the Democrat party.
And, there is a tendency for the liberals to attack and denigrate those who disagree with them as racist,sexist, bigoted, homophobic, and all of that. There are no honest policy disagreements with Democrats, instead, you are attacked as some sort of bigoted monster.
For these and other reasons, you see many working class people who just can’t identify with the Democrat party and its causes.