At the height of American racism toward various groups (Blacks, Mexicans, Jews, Indians, Asians, etc.), the racism or bigotry wasn't usually based on real threats posed by those groups. It was more based on maintaining the "social order" or hierarchy, where White Anglo Saxon Protestants were at the top of the heap. Even White Catholics were looked down upon and discriminated against, in the North and (especially) in the South. John F. Kennedy being a Catholic was a BIG DEAL in 1960 America. From the forming of the Republic up through the 1950's and into the 60's, there was more of a class system here than many want to admit. It wasn't as rigid or structured as the various 19th Century European aristocracies, but it did exist. Even for Whites, there was a blue blood class and there was the poor White class - and they did not mingle. There was more of an effort then than now to make sure that people "knew their place". We don't really have that for any group these days - certainly not in legal terms and not even in social terms.
I read the Washington Post piece in the OP, and though I understand the premise, I'm not sure that I agree with all of it. I'm not sure how one would accurately measure racism in quantitative terms, because the exclusionary laws and practices of the last century are now illegal. So much of what was mentioned in the piece really CAN'T legally exist now. From restrictive deed covenants, which prevented present and future owners of real property from selling to members of prohibited groups (non WASPS), to broad Jim Crow like laws that applied to various groups on a sliding scale, those are all illegal because of various civil rights laws. But really, I just don't think that the nation on whole (or the world) is as racist or "classist" as it once was. Maybe Asians have seen a more dramatic reduction in racism than other groups in relative terms. I just don't know you'd measure that relative movement.
As for people who want to quote crime stats or supposed social issues to justify their feelings about one group or another, that's called rationalization. Whether it's the KKK or N.O.W., the weak minded among us tend to do that. Their feelings would be the same, but now they have a "reason" to lean on.