I worked for a big tech company for a while, and there were a moderate number of black engineers. Not tons, but not "almost none" either.

Politics is harder to judge. At that big tech company, it was not safe to be conservative, or indeed anything other than the extreme left. In my time there, I found maybe a dozen people who could reasonably be described as "conservative" -- but because being outed had such strong negative consequences, I'm sure there were tons more that I never detected.

None of the black engineers that I knew expressed explicitly conservative views, though one did mention quietly that they didn't like how uncomfortable everybody made it for him to express his Christian faith and the degree to which it was just a tacit assumption that everybody was atheist. Religious, though, isn't the same thing as conservative.