Ghana, has several advantages over Nigeria that better fit the presidents agenda. It is a stable economically and politically. Ghana enjoys a high economic growth rate: 6.3%, per capita income and standard of living compared to the rest of Africa. Politically, Ghana recently completed the transition of power from one party to a another. Also there is oil.
Nigeria has a record of corruption, military repression and oil fueled violence.
In an exclusive interview with a journalist from AllAfrica.com website, Obama said, "part of the reason is that Ghana has now undergone a couple of successful elections in which power was transferred peacefully, even in a very close election. President Mills has shown himself committed to the rule of law, to the kinds of democratic commitments that ensure stability in a country. I think that there is a direct correlation between governance and prosperity. "
Basically, they had a close election. They transitioned power peacefully and they should be rewarded for their success. Nigerial and Kenya had the opposite action when they held recent elections.
Obama arrives Friday Evening, July 10th, 2009 and will stay for a 24 hour period.
Sources Used: Allafrica.com