The truth is though that ultimately, politicians are gonna be malleable to those who are going to vote

No, they are not. A single donation from a billionaire would buy more press to get more voters from name recognition than a million working class supporters. And if the politician betrays his base, the most he can fear is losing reelection, and even this is not assured. If a politician goes against billionaires, he is going to be smeared, harassed and have his opposition funded. This ensures that the only politicians in any significant elections are already guaranteed to serve billionaires.