Yes, discrimination against men, and or white people is illegal. They can show though that they hire plenty of white men. You are correct in California you cannot discriminate against employees due to politics, however I'm sure they'd be able to show they hire plenty of republicans. It is also an uphill battle for Damore since he'd basically be claiming that he was discriminated against at the same time as arguing that they shouldn't do more to balance the apparent discrimination against women. Whether or not any of that is true, it's going to be a hard sell to a California jury