In an earlier report for Tablet, "America's White Saviors," Zach Goldberg shows that the white liberal fixation on discrimination extends beyond concerns about the historic wound of slavery: "The percentage of white liberals perceiving 'a lot' or 'a great deal' of discrimination against immigrants more than doubled between 2000 (29%) and 2013 (57%)." I'm willing to bet data would show a similar increase in white liberals' perceptions of discrimination against gays and lesbians.
There are many reasons why white liberals lead the way in damning America as racist, bigoted, and homophobic. As many have noted, being "woke" is a religious phenomenon. Joshua Mitchell has observed that the de-Christianization of large sectors of American society, especially among white liberals who are heavily represented among the "nones," leaves a large reservoir of unaddressed guilt. The weight of sin becomes oppressive, prompting people to search for scapegoats. Given our national history, the sin of racism becomes a powerful explanation for feelings of guilt. Identifying and condemning "white privilege," especially the privilege of straight white males, allows non-religious Americans to offload their guilt, either by charging others with racism or through ritual confessions of their own privilege and vows to "do better."
The accusation of racism also serves as a powerful canceling device, an important weapon in the arsenal of the white-dominated liberal establishment. To charge a person with racism is to disqualify him from any role in society.