> * talk about racist policies against the Chinese in California in the 1800s
Which does not directly affect current discourse, being removed by multiple generations from those alive today.
> * talk about racist policies against the Irish and sentiments against Catholics throughout the country even just prior to JFK's election in 1960
Sure, but then you're bringing religion into the mix. That seems unwise when trying to make a specific point that to that point has not included religion. It will just muddy the waters.
> * talk about racist views and policies towards interracial marriage in the South and Southwest
Also applicable, but less well known.
The point isn't to correctly spread the blame for bad behavior around equally, it was to explain why Americans have thin skin regarding race issues. The South is a valid example of this,and is the common example because it is so well known and recent. That may strike you as unfair, but fairness wasn't the point, communication was.
However, if you are trying to contrast things fairly, we could say:
* talk about racist policies against the Chinese in California in the 1800s
* talk about racist policies against the Irish and sentiments against Catholics throughout the country even just prior to JFK's election in 1960
* talk about racist views and policies towards interracial marriage in the South and Southwest
That's contrasting different experiences in time and place. That's being fair. The alternative...