He is saying this because rank-and-file blacks have woken up to the scam. He wants the Dems to continue to pander to the "black community" to keep them down and broken.
Notice that he and other rappers WERE SILENT during the Obama years, when Obama did nothing for blacks (and he shouldn't - it's time to stop treating blacks as some preferred group, but you get my point). Obama did nothing for blacks, and people like Cube didn't care because they were still getting paid and fed.
Thanks for the question, EEE. At a quick glance I’m seeing that maybe he sees a bigger picture. If I misread, I’ll apologize. I’m thinking maybe he’s had a Kanye enlightenment. I’ve been wrong so many times in my life that I cannot count or recall them all. My wife does accuse me of just reading headlines. I know that I looked at this fast and may not have put it into context or read between the lines. I might go back for another glance. Live at my house moves pretty fast...
https://www.youtube.com/watch?v=vsYBtfQ3QDo