Money has a huge influence on politics, and recognizing that reality isn't the same as wanting it or encouraging it.
I don't really object to you asking this question, but I do object to you calling a rhetorical question "an honest question".
For many, it's not just an intellectual position but an emotional one. This doesn't necessarily mean it's wrong, but you probably won't be able to reason them out of it. It's the same reason I don't listen to Michael Jackson. He's dead and none of that streaming revenue would go to him or to raping children but...yuck.
At the end of the day, there's an irony in this guy supporting the very freedoms on the internet which are being used to disseminate criticisms against him, and perhaps inducing people to starve one of the vehicles which helps maintain those freedoms.
I'm kinda confused here. The context of this is that a rich tech bro uses his money to fund and promote a political party, with our money, but we can't decide to not pay him because that's influencing money with politics (???)
What kind of bizarro world is this, he can use his vast wealth to promote racist parties but we can't collectively use ours? How about he just "does it at the booth" and donates his money to the against malaria foundation?
I'm suggesting that small political progress is simply not worth witch-hunting for. If you have political concerns, engage by voting, starting your own party or advocating for your cause instead of ruining the career of a person you disagree with.