This is a version of a comment I originally posted at Iain Dale's site about the chaos that is breaking out in Kenya at the moment, and the more general democratic failures in Africa.
One of the main problems that Africa has is a lack of nation states. Almost every country is an amalgam of several different and distinct ethnic groups which encourages politicians to pander to ethnic prejudices and encourages voters to overlook massive corruption as long as their local politician can divide some of the spoils to his own ethnic group.
Be honest, if the EU ever becomes a country and controlled most of the continents public sector revenues wouldn't you be more inclined to overlook a corrupt British politician if he brought home some of the wealth than you would if a current politician did so?
Botswana is an exception to the rule in that it is basically a nation state (there are small minority groups but they aren't numerous). Botswana is also prosperous and stable in spite of a sever Aids epidemic and I don't believe that this is a coincidence.
Update: Julia in the comments points out this map over at Laban's blog which illustrates the point about the ethnic mish mash that is Kenya:
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