Lying to get into office and pursuing legislation that is supported only by moneyed special interests are probably both corrupt things a politician can do, and they certainly erode trust in the government. But the don't get tallied up in the same way quid-pro-quo bribes do.

In many places and times, governments have been pervasively corrupt, so that for example, in practice you will never get a drivers license or a building permit unless you first bribe the inspector or officer who needs to award the permit. This type of corruption is on the decline in almost every country. To my (limited) knowledge it has been relatively rare in the USA throughout its history.