A loyal Marginal Revolution reader asks for discussion of:
Latin American politics. Why do our politicians suck.
Assuming that they do suck -- most of my own information on this point comes from the novels of Mario Vargas Llosa -- the obvious suspect is a culture of unaccountability. In particular, governmental failures of almost any sort can be blamed on American imperialism, which for Latin America is actually a closer and more real memory than the vague "colonial oppression" constructed by Arab societies.
Notice that defining policies in opposition to America is not equivalent to offloading accountability. For example, social welfare policies practiced in (e.g.) France are presented as a conscious alternative to "ruthless Anglo-Saxon capitalism"; but this is an attempt by their architects to claim responsibility for success, not to disclaim failure.
Another relevant point is that, due to the generally more hostile topography of Central and South America, even a nation which looks quite small on the map might be divided into isolated regions. This in turn makes regionalism an attractive strategy for politicians, despite its overall negative effects. In short, many governments are insufficiently federalized for the effective size of their countries.
[Tyler Cowen answers here.]