Pretty darn corrupt. It’s at all levels and it takes many different forms.
The thing one must keep in mind is that governments by their nature are corrupt. To a limited degree they are necessary but when one group has the ultimate monopoly of force there is always going to be sketchiness.
Not that corruption can’t happen in the private sector too. But it is interesting that corruption seems to spike in the private sector the closer it comes to government. Think road building contracts, liquor licenses, pension funds for state employees etc.
Click here for a pretty damning list of instances of corruption in the USA. Though it only scratches the surface.