Some where between 60% and 80% of personality, the choices you make, and the resulting outcome comes from genetics depending on what scientific study you believe. Either way, genetics play a big part in who you are, race is coded into genetics because of choices and actions of your ancestors. You can mix races up, but all it does is create a new race that is very small (at least to start) and behavioral science has shown that the vast majority of humans chose someone who looks like themselves to mate with when given the free choice.
The Left used science to blow up religion, but the vacuum of beliefs was filled by science believers and most believers do not think for themselves and are easily manipulated by the perceived consensus. So now the Left has decided that the science around race is a threat to the utopia they think will come about if race dissolved and have tried to educate what people see with their eyes and perceive with their perceptions out of the population.
Race is not predictive when it comes to the individual, but it is when it comes to groups. In large groups like Black or White, the predictability breaks down even more because the diversity of genetics is so large.
So both sides are in part correct: Your race and more so your direct family have a lot to do with who you are and what you decide to do, groupings of similar genetic makeups have similar behaviors, strengths and weaknesses; and judging an individual based on the color of their skin vs the content of their actions would be only slightly better accuracy than flipping a coin.