If presidential candidates were mandated to take the following steps before clinching their party tickets, Nigeria would never have any bad leader:

1. A declaration of a net worth of at least $1 million worth of assets.
2. Background checks on each standing source of income.
3. A down payment of over 40 million naira to participate in the election.
4. A psychological analysis, mental health check, and physical disability check.
5. Lie detector test to ensure that several things are as they seem:

A. Source of wealth is legal.
B. Haven't engaged in corrupt practices in the past.
C. Real intention for choosing to become president

6. Notice on the fact that regulated presidential debates are on a mandatory basis. Absence more than two times and without any real stated reason would lead to automatic disqualification without refund.
7. Each debate would be carried out in person, ie., There won't be any one working on a representative basis.
8. Lastly, he or she would have to go through an experience that would be the most tasking both financially, mentally, spiritually, and physically. Each member would be mandated to undergo a six months rough experience. Which would involve leaving all his/her monetary comforts behind, moving the a location in one of the poorest and most unstable communities in Nigeria, without the comfort him/her is used to, completely off the grid (no cell phone), living as a local, in physical disguise, in a hut or however the local has to live. Said person would be monitored daily to see if him/her cheats or tries to wiggle his/her way out of the full experience. A temporary job would be provided (pay would be minimum wage for the duration of the experience), mandatory slimming exercise would be carried out before the experience for ease of blending in. Zero guarantee that the person would come out safe and alive (although one security detail would be provided who would also have to live with you in disguise for the duration of the program).
Upon completion, each candidate would not just say that they know what the problems of the society is, they'd have lived it. Anyone unable to go through or complete the experience would be asked to withdraw or be disqualified without pay.

All steps also required for vice presidential candidates.

These steps are stated before hand, so each decision to be the President of the Federal Republic or Nigeria is a deep conscientious effort, one borne out of a strong genuine need for change any not the many dubious reasons we have today.