I believe all politicians are corrupt on some level. I have my doubts it is possible to join that field without being exposed to corruption and often times people get pulled in and put in a position where they can't refuse. For this reason I think it is reasonable to assume all politicians are affiliated with corruption to some extent.
No person acts selflessly, as much as they claim to you and themselves that they are. Politicians become politicians not because they want to help people or their communities, but because they desire power and admiration. So many politicians become corrupt or are corruptible and no voters realize it until it's too late, and that's not on them - even the politician didn't know.
All politicians are not corrupt on some level. I think that just with any profession there will be some corrupt people out there that will make the whole organization look bad. I think there are many politicians out there that are trying to do the right thing. Many of them get caught up in the greed and profits.
I do not think that all politicians are corrupt on some level. I think that while a lot of politicians may be corrupt on some level, I do not think that all of them are. I think that there are still a lot of politicians out there that are decent.
Even though it's often easier to distrust people than to trust them, I would like to hope that at least some politicians really care about the people they represent and are good people at heart. One of the problems is that power can corrupt, so if people are in politics for the prestige and popularity they will receive from it, then they may go "bad." Overall, though, I have to trust some, especially small town politicians, are people in the business altruistically.