I suppose there's an element of politics which is, if not quite corrupt, corruption-adjacent. Most of us get that literally asking for money to, say, hand out a Senate seat, is corrupt. But of course there are a lot of "deals" way short of that which are just politics. I'll support your whatever if you support mine. I'll endorse you if you agree to back this. I'll vote for your stupid bill if you put my person on the oversight committee. I'll donate $18 million to your political party if you agree to (??). You have my support for your city council run if you take care of my little zoning problem. OK that last one sounds dirtier, and it probably is, but I do think local politicians manage to get themselves in trouble in part because the "deals" are smaller and narrower and it's a bit easier to see how they're just bribery (also the FBI loves to bust "urban politicians" which is an issue even if they deserve it).
But my point is not to argue about which of these things is corrupt, illegal, or just politics. My point is that most politicians spend their careers living in this world of "compromise" where those compromises are always just a little bit dirty, at minimum. Only certain types of people can handle that. Only certain kinds of people like that.
