Over many years I have known many white vets turned down for USPS jobs because of quotas. Not drug users, no police records. good background records. While I am at it let me tell you about the IRS. I did service work for one of their main branches. The white guy maintaining their computers told me many times how he was being passed over for a promotion by blacks over and over. I have been around the block a few times and could tell you of many other times whites have been passed over.
I agree that the hiring process and promotions for government jobs is insane. Nepotism, cronyism and other issues show their ugly head in hiring and promotions. Seen many times, where certain people have the "birthright" to positions.
As a partially disabled Veteran, I have had to point out to hiring managers, etc., the statutes that are used in hiring of disabled Vets. They are not happy to acknowledge them.
We have to remember that a Veteran can be male or female. White, black, Indian, Asian, etc.. So the term "Veteran preference" can mean that the Veteran can be either gender or any race. We all served.