I think to understand the "new" Left, you have to understand the new definition of Racism from CARED (Calgary Anti-Racism Education). I would suggest reading the whole website to understand their thought process (I had to sit through an Anti-Racist seminar for work, and I have some thoughts about it that undercut their messaging, basically they don't like Multiculturalism).
www.aclrc.com
So basically only White People can be Racist. They even give a term for everyone else: "racial prejudice". A term not as loaded as Racist or Racism, a term that suggests it is just prejudice, so they can change, while White People cannot.
The key metaphor is water (racism) in the fish tank of society.
A little history to understand where they are coming from. In modern history, White European Societies have been the dominate Culture throughout the World. Permeating itself in every dark corner of ALL societies. Through Media, in-groups, representation, everything. And People internalize it, "Whiter" black people are treated better by cops, Whiter Indians (from India) are thought of as more beautiful, Chinese People want to make themselves whiter (I think it is to do with class, tan vs not tan, office works don't get tanned as much as outdoor manual labour).
You can see these products on Amazon:
https://www.amazon.com/skin-lightening-cream/s?k=skin+lightening+cream
And from Centuries of War and Fighting, their technology advanced much more thoroughly than other societies making it easier to conquer and rule - they don't say this part, just me editorializing .
And since this culture is White centric, it promotes White People above all else. Sets up systems that promote and lift up White People. Or just help the people of the Ruling Parties Countries.
So since these Colonial European Countries conquered and ruled land that was not indigenous to them, they thought they are superior and of better Race/System/Governance/Culture than the "Savages". Think Eugenics. So this theory/term of Racism is only a White European theory/term to describe this thought process and can only be attributed to White People.
*I think if they were intellectually honest, then they HAVE to come up with other "terms" describing other Cultures/Peoples "racism" that is on the same "level" as "racism".
It is about Power. White People (as a whole) have more Power (freedom, society's acceptance, systems, etc.) over BIPOC (Black,
Indigenous, People of Colour) and consciously or unconsciously wield it over them.
So for people on the left and gen Z, who have been steeped in this theory, see a White* Rich Nation brandishing their Power/Racism over "poor" "Colonized" People of Colour, and you see why they support a "resistances" Genocidal Terrorist Organization that brutalizes their own people and want to ethnically cleanse all Jews of the face of the earth.
*Never mind that there are Black Jews, Arab Jews (Sephardic Jews), and Brown Jews, Isreal is just a White European Rich Nation of Jews, so you get a coalition of Anti-Racist and Anti-Semites. Weird bedfellows indeed.