Okay, the one thing I question about the Lightwoods being mixed-race is…I feel like a lot of their characters, as people, came from their privilege. Part of the divide between Alec and Magnus was that Alec comes from this place of safety that Magnus doesn’t have, either as a POC or as a warlock….
I guess it depends on if the show goes along with what Cassie said in that race is treated differently in the shadowhunter world. If it is, I don’t think their attitudes would change because they have little to no interaction with the mundane world and wouldn’t be surprised if they were completely oblivious to the racism. Being shadowhunters they may not have experienced any discrimination for being POC or coming from a mixed family so they would have that empathy for downworlders or share that experience.