Most politicians often fail not because they are stupid, inept or corrupt. They often fail because:
To be elected, and in their desire to be loved by the electorate, they make false promises.
The electorate, once realizing it has been deceived, responds with frustration and anger and the cycle repeats itself as the electorate is attracted to the next politician making false promises.
Reality is there are no political messiahs or simplistic answers. The electorate must get involved and work together to solve its problems. Everything else is hyperbole and unmet expectations.