What ought to be done is always cat belling*:  The key is how to achieve it?

In the political arena that means a constant repetition of the truth: That politicians are not magicians, that things do not get magically better overnight because a particular politician gains power,  (but they can get dramatically worse) and that slow steady progress is all that can be achieved, corruption by corruption.
There are no easy answers, otherwise who would tolerate the political process?

All that good men can do is form alliances with other good men, and do things better at whatever level they find themselves at. 

Reward good behaviour when you find it and condemn the bad.


*https://en.wikipedia.org/wiki/Belling_the_cat