The only way corruption like this can be defeated by a president who is different from other leaders who have served in the past, is if the citizens of that country can fully support and stand by their president. If other bad politicians sees that majority of the citizens are against corruption, I think it will be tough for them to go against the president.
Like in South Africa, it was easy for Nelson Mandela to fight for good governance because he was fully supported by other citizens of South Africa .
That was then, the citizens of then differs from nowadays citizens. And the government differs again. Meaning, the kind of people on government sit now are heartless and doesn't have human sympathy.
Everyone on government sit are swallowed by corruption and they can do anything possible just to maintain that because of there selfish interest from president down to the lower positions. The citizens are on their own and can't even protest against them, small protest now you will see forces (police, army and other para military) dispatched to disrupt the peaceful protest.