Today the American left hates the working class with such intensity that the left is comfortable with the left’s alliance with the One Percent and the military/security complex against Trump.
The answer seems to be Diversity Politics. In 1860 blacks had the burden of wage slavery. In 2017 all have the burden except for the rich whose income is in the form of capital gains and those among the poor who don’t work. Identity Politics cannot present today’s wage slavery as the unique burder of a “preferred minority.” Today those most subjected to wage slavery are the white professionals in the upper middle class. That is where the tax burden is highest. Americans living at public expense are exempted from wage slavery by lack of taxable income. Consequently, the liberal/progressive/left only objects to 19th century wage slavery. 20th Century wage slavery is perfectly acceptable to the liberal/progressive/left. Indeed, they want more of it.
Here is an example hot off the press. This month in Cobb County, Georgia, a car was pulled over for driving under the influence of alcohol. The white police lieutenant requested the ID of a white woman. She replied that she is afraid to reach into her purse for her license, because she has read many stories of people being shot because police officers conclude that they are reaching for a gun. Instead of tasering the woman for non-compliance, yanking her out of the car, and body slamming her, the lieutenant diffused the situation by making light of her concern. “We only shoot black people, you know.” This is what a person would conclude from the news, because seldom is a big stink made when the police shoot a white person.