Botswana is one place where there is a functioning democracy but a fairly poor electorate. There has never been a coup, and all elections have been open and fair.
Of course, this is due to the influence of Seretse Khama, one of those fairly rare people who do not covet power, but instead work to improve the country. He made sure that corruption did not take root in Botswana, and for many years the most feared government minister was the Inspector General. (As opposed to most African countries where it is the head of Internal Security!)
Since that time, the BDP (Botswana Democratic Party) has stayed in power.
Khama was so succesful that the BDP has never had to suppress it's rivals. Their support has been declining in recent years, but they are still the dominant party.
Democracy doesn't need a firm economic foundation to survive, but it helps immensely. In fact, Botswana is a fairly special case, and is probably the exception that proves the rule.