Are Politicians Who Go To Jail Being "Set Up"?

Washington DC Mayor Marion Berry, known for a drug and sex scandal that got him arrested and nearly destroyed his career, has written a book that claims he was set up by his political enemies who didn't like the fact that he was helping Black contractors get government contracts. A number of elected officials, both black and white, have been indicted for committing illegal acts or condemned in the media for committing immoral acts. Is it because they are being targeted by their political enemies? Or are they the victims of their own greed, lust, and addictions? How does an elected official avoid falling from grace