All politicians will become corrupt. It's a matter of time and length of service. The longer they hold power, the higher propensity to be corrupt. Human nature is like that. Politicians started fighting for a good cause. Then they slowly degenerate into scums, tempted by the money in the business world. So they open themselves to business lobbyists and ignores the concerns of people who voted them in. Priority becomes imbalance in favour of businesses over citizens. Then one day, either thru the ballot box or people's revolt, violent or otherwise, they get thrown out. A new group comes into power and the process gets rinsed, recycled and repeated all over again.
Life carries on.