Note that "hostile work environment" is a legal term related to a pattern of behavior taken to intimidate someone based on a protected trait (e.g., age, sex, religion, race, disability, etc.).
Notedly, political viewpoints are not a protected trait.
Notedly, political viewpoints are not a protected trait.
If you did that kind of stuff at most places I've worked, you'd get fired for it, regardless of whether it fit the legal definition of "hostile work environment".
If the behavior is because of your race and they aren’t fired, you can (successfully) sue your employer. That’s the difference.
In her letter, she asserts that behavior that fits the first scenario is illegal- it’s not.