Your take away from the original study was fear of crime? Now I understand what our problem is — your basic logic skills. This is like a basic LSAT question you got wrong.
Edit: the quote is right on. Your statement that it wasn’t racism missed the point of the authors quote. Try again and see if you can see where you missed.
And no, I didn't miss anything. Fear of crime ≠ racism. And unconsciously associating crime with blackness also is not racism when, for example:
"According to the FBI, African-Americans accounted for 39.6% of all homicide offenders in 2019, with whites 29.1%, and "Other" 3.0%".[1]
So 14% of the population, but almost 40% of the homicides[2]. That's a rate almost 3x higher than you would expect from the population numbers. And whites are 61.6% of the population, so their share of homicides is slightly less than 1/2 of the expected rate. If you combine these two figures, you find that blacks have a 6x higher per/capita share of homicide offenders than whites.
Now this is all very unfortunate, problematic etc. But unconsciously associating blackness more strongly with crime than whiteness is not racism, but sound statistical reasoning based on the real world[3]. And humans are generally very good natural unconscious statisticians, particularly when it comes to assessing personal danger.
And please note that I am not in any way claiming that this association is "intrinsic" or that it is fair, or saying anything about the causes of the disparity in crime rates whatsoever[4]. I am just showing the unambiguous fact that the association is based on reality.
Also note that even if, in spite of the facts, you still hold that associating blackness with crime is solely or primarily due to racism, it would still not support your original assertion that "For example, when whites are told that the legal system is unjust to blacks, they tend to support it more." and certainly not your assertion that "most whites do, at some level, prefer blacks not to do well." That's just complete BS you made up.
[2] Homicides tend to be a good indicator because they are fairly unambiguous (there's a dead person) and also tend to have less chance of inconsistent investigation than other crimes.
[3] Note that this only applies to such unconscious associations as was the case here. It does not justify other sorts of inferences, particularly on an individual level.
[4] Except that, particularly for homicides, it isn't the result of unfair policing practices in any way that comes close to explaining the actual disparity, see [2] as well as the research on racial disparities in the criminal justice system, which came to more a 10% divergence, so nowhere near the 6x difference we see here.
Edit: the quote is right on. Your statement that it wasn’t racism missed the point of the authors quote. Try again and see if you can see where you missed.