We draw from an all-volunteer force. Unless you can show me statistically where MEPS has made a habit of turning people away due to their skin color, religion, or sex (wherein we'd definitely have a problem), tell me where the Air Force is culpable in recruiting only a certain demographic. There may be multiple cultural norms or perceived perks in place which made military service much more palatable to one ethnicity or another, but these are all individuals deciding to sign on the line.
If we go to a draft and specifically target minorities under the guise of creating a more diverse force, well, good luck with that optic.
The minute we start recruiting specifically in the mindset of giving preferential treatment towards ANY gender, race, religion, background, education, creed, etc., we're no worse than the days before segregation, even if the intent of this is to "diversify our force". The same holds true if the service is showing anyone the door based on an attempt at shaping the force towards some sort of quota.
At the end of the day, service, promotion, and retention should all be based on merit and capacity to hack the mission. Strip away any indicators on all records as to where a person comes from and let their bullets do the talking.