Most sources on Roddenberry’s political beliefs are people who knew him, and they didn’t open up about those beliefs until after his death. Here’s an article that I’ve skimmed:

According to his last wife, Majel Barrett, he identified as a communist. But we know from the many accounts of his unethical business practices that he was also obsessed with making money. He preached peace and love but was infamously difficult to get along with. And he flew the flag for feminism while being a notorious womanizer.

Gene was delight man with great creativity and talent, but he was also a deeply flawed man who often failed to practice what he preached.