I've asked this before, but do you care to support this with specific examples.
Less than liberal or fair-minded--includes the issue from last week's episode; the father claims "the only thing they hate more than a Mexicano is a homosexual" (they--meaning white people in America, given the course of his stories), which is the showrunners' disrespectful way of showing how much they want to sell homophobia as the greater form of discrimination, when the history of the U.S. (where Supergirl happens to be set), and the world forcefully, repeatedly proves the polar opposite. Hell, with every passing day, we have a rise in Neo-Nazi/Klan/Skinhead/other groups in the U.S. (again, where Supergirl is set) and dominating the top of their neverending rallying cries are racial minorities, which they--as always--paint as the greatest threat to their survival. Yet the whites the father refers to hate gays more than Mexicans? Offensive and ridiculous in the extreme.
As a minority, I find that the kind of conscious downgrading of racism as the lesser form of discrimination to be the kind of opportunistic, bankrupt messaging (of generally white Hollywood liberals) that in the real world had (for one example) innumerable African Americans argue that they were not voting for Clinton (last year) because she--and the Democrats have long taken them for granted (and votes), while placing their greatest interest (gays) as their national priority. The point being African Americans believe they were being used to win elections, yet for all of the Democrats' "we support you" sing-song & glad-handing, socially and politically, that ever-threatened group feel they have little support from them, particularly when the like-minded in entertainment media sell messages like the one in question. The beliefs and actions of allegedly liberal minded people are loud and clear;.no one truly interested in fair minded truth would script something so false.
That's just one of the specific examples.