If the politicians enters in the world of bitcoin, I think there is a chances that bitcoin can lead to corruption. Even there's a chance the corruption of bitcoin, it will never be happen anymore because developer would not want it to happen because they know that bitcoin corruption can lead the bitcoiners to quit using bitcoin.
Actually, some are using bitcoin as way of transporting money illegally such as that buying drugs, and any other forms of illegal. It cannot really avoid, knowing some people will do everything just to earn easy money. And when it comes to government, they would do such thing if they would discover this, they can hide some of their money by buying bitcoins and we cannot control it.