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 .
It's absolutely and practically impossible for one to enforce a law he or she is not willing to obey.
Remember, it wasn't all South Africans, both the elite and great political influencer were in support of Nelson Mandela, even his own wife didn't see light in the midst of that darkness.
But the mindset for a total positive change prevailed
Determination, perseverance stood fast.
So we can't truly and successfully fight corruption being compromised.