> Absolutely. African Americans were excluded from its benefits by a viciously racist society. We should rectify that today.
https://www.merriam-webster.com/dictionary/rectify
You are arguing against something he did not say.
So to make it easier for you, he is saying:
1. We should correct the wrongs that we have inflicted upon African-Americans in the past, including opportunity costs. 2. We should also recognize that making an investment in all people is a net benefit for our society
I don't know how to make it any clearer than that.