There are many problems for democracy. For example, there is high poverty which creates tension for liberal democrats since many people believe that a non-democratic regime would actually be better for solving such issues because of things like command economy or by forcing capitalists to redistribute their wealth or similar things.
Another problem is the military tradition where the military seems to have problems getting accustomed to ideas that they serve the people and not the government so it creates a problem whenever there are things like protests because the military usually intervenes in a controversial and often brutal manner.
Another huge problem is the voting tradition. Although originally they used to have high voter turnouts after they ended their totalitarian regimes, many Latin American persons have grown dissuaded with the idea of democracy and voter turnout has been reduced dramatically compared to how it was before which only helps the established governments stay in power.