Kant on human differences

Kant's Categorical Imperative is, "Act only on the maxim that can
become through your will a universal law of conduct." For example,
lying is wrong, because if everyone lied, it would defeat the very
purpose of trust.

What if we based our maxims on something particular about one group of
people, such as race? My maxim would be, "If it happens that I am
white, then I may..." This appears to be a flaw in the Categorical
Imperative.

For a long time, I did not know how Kant would respond, until I read
this from an abridged translation about a kingdom of ends:

"Laws determine certain ends as universal, and hence, *if abstraction
is made from the individual differences of rational beings* (my
emphasis) ... we get the idea of a complete totality of ends combined
in a system ... we are able to conceive of a kingdom of ends ..."

Let's discuss this.

First of all, it is not clear what Kant means. Second, it has been
said that genetic variety is im****tant for species survival. Third, we
know that normal rules of duty cannot apply to people with certain
disabilities. These are three problems that Kantians must face.