Today, it appears to be a significantly smaller factor (or non-factor) than most people seem to think it is. “Most people” includes both the URMs who think it is a huge hook for themselves and the people who resent what they perceive as a huge hook for someone else.
If you were White or Asian and applied to schools like USC last year, as an aside, I am neither… then you saw the effects of race aware admissions policies. White and Asian applicants well above their admissions theresholds did not receive acceptances where less represented demographics did. I’m not making any judgement on whether that is right or wrong, but at some schools it makes a difference.