Nations are made up of people, governments are supposed to be operated by people chosen by the people. The Founders created a republic for a reason. Since they were educated in the classics, they understood that democracy always turns into something else, especially when it is direct democracy or 'pure' democracy. Even the creator of Marxism understood this, as well as the infamous communist, Lenin.
Our nation's political climate began with two factions – Federalist and Anti-Federalists. Later these became political parties and developed into what the main parties are today – Democrat and Republican. Today, the Democrat Party has come to full circle and has shown that the Founders were correct and so was Karl Marx.