This is merely an anecdote, but looking at the overall landscape, I would imagine this is more common than you think:
My father works for an arm of NASA. His group, and I assume the entire apparatus, are actively tracking how many women and minorities that are being hired. Reports on the diversity statistics are provided to hiring managers on a semi-annual basis. During his last review meeting with his manager, he was congratulated for the progress his team had made in this regard. "Keep it up. We can do even better." The impression he's been given is that given the choice between two closely qualified people, it's better to get those numbers up. So now it's not good enough to be the best candidate as a white male, you need to clearly the best candidate or else you're at a disadvantage.