There are reportedly over 800 billionaires in the US. We hear about maybe 20 of them. I suspect 700+ live quiet lives, perhaps trying to make a difference with donations, etc., and are not politically very active or interested, or least are not publically known as D or R.
We have one pair here who started Home Depot, one is very well known (Arthur Blank) for donations etc., the other is almost never in the news except he passed on recently. I'm "told" the other quiet one donated a lot of money to various local causes. Neither seems politically involved, but Blank probably is quietly.
My wife is close friends with one (she's French, not American) and she's an example of one who lives quietly trying to help where she can. I think a lot of them value anonymity and avoid the public eye, no doubt some donate politically, but quietly. So, we don't know in which direction they lean.