A bribe is usually understood to be of benefit to the politician personally. This sort of corruption is actually incredibly rare in the US.
What is, unfortunately, very common are payments to their campaigns. These are legal and, since Citizen United, basically unlimited. There are, however, rather strict rules as to how they can be used. And as that Republican idiot from California is currently experiencing, these rules are enforced.
I'm not making apologies for the undeniable harms of the latter practice. But it is different, and marginally less evil . As to the relative evilness: the "traditional" bribe is strictly more useful to a politicians, because they always had the option to convert it to campaign money. That option does not exist in the other direction.
I think it's important to appreciate such nuances. First, because it stops the corroding effect of cynicism on your soul. And, second, if we condemn everything at the same level of maximum evilness, any change that is not instant paradise is indistinguishable to the status quo. Because Paradise no longer exists (or is now a strip club), nothing will ever happen.