I think it is a sad state of affairs when the only people who can even be eligible to get elected have to be corrupt criminals because decent honest people can't even get past the early stages.

The large collection of vested interests who manipulate these things seem to like the those who are corrupt for a variety of reasons but I think these are the main 2:

1. They have little or no conscience with strong sociopathic tendencies so they can be relied upon to do things the average person with a conscience would refuse.
2. Their history of legally dubious and outright illegal behaviour is an extra tool of manipulation that can be used to control them if they get ideas above their station.

The choice between bad and bad is not really a choice at all.