So, as a disclaimer: I have a degree in history. I came into this course knowing that history is important and knowing a lot of these examples of historical racism. So obviously, yes, I think that the history of racism still impacts the US today and is the reason why white supremacy is still going strong.
History helps us create lasting stereotypes. Stereotypes help us justify institutional racism. This creates a vicious cycle, as institutional racism also helps confirm the stereotypes. For example, the stereotype of Native Americans becoming addicts can fuel the idea that they need to be adopted. As we heard in the story, some adopted children became addicts because their family was broken. Racism thrives off this cyclical logic.
History also gives us an easy out. We can say that we aren't racist now because we don't spray immigrants with toxic chemicals, but that doesn't mean we aren't being racist in other insidious ways. The switch from Jim Crow law to "law and order" is a good example of this and one that Lee Atwater manipulated to continue perpetuating lasting and effective racism against Black people.