The number of electoral votes can constantly change. This is because the number of votes a state gets is the number of representatives and senators in congress. Since the number of representatives is based on the population it can change. Every ten years the US takes a census to see the population of each state, then based of the results decides how many representatives every state gets, this then changes the number of votes every state gets. For example, in 1960 there were only 537 electoral colleges in the US, currently, there are 538.
Direct democracy was not what the framers of the United States Constitution envisioned for the nation. They saw a danger in tyranny of the majority. As a result, they advocated a representative democracy in the form of a constitutional republic over a direct democracy.