I don't live in Nigeria, so I don't know how the government set up is working in actuality, but the framework for the best governance the world has ever seen is there:

Executive branch—President

Legislative branch—a National Assembly compromised of a House and Senate

Judicial branch—Supreme Court

A Constitution, which becomes the ultimate law of the land

Compromising a constitutional republic, rather than a democracy

A separation of powers, with checks and balances, and more than one party.

There are other things that get thrown into the mix, and other voices to account for, but that seems to be the gist of the Nigerian federal governance.

For all intents and purposes, it was modeled after the federal government of the United States.

Which means that the pieces are there for the best governance man has known throughout history. Unfortunately, that does make it flawless, nor does it necessarily incentivize the people in positions of power to use the system as it was intended. Instead of a separation of power, or decentralization, there are many who want to concentrate it wherever they are, for their own benefit.

So, as I think of it now, governance is only as good as the people who are elected to fill the respective positions, which means good people need to run, and voters need to somehow discern who those folks are. By good, I mean that they understand how the government is intended to function, and that they are content with the level of power they are given, and that their purpose is serve their constituents, and not serve their own self-interests.

If you have a bunch of humble, selfless people running around, there's bound to be more good coming out than bad. Mistakes are made, but they are learned from and a better way is established.

Centralization of power more times than not leads to bad governance. Consolidation of powers into one person or body, particularly a body of people who believe a certain way, or are willing to be coerced into a certain way of thinking, is not good for those who are outside of that body.

The trick is, keeping that balance of decentralized powers.