The primary advantage of the electoral college is its ability to simplify elections; its primary disadvantage is inequalities among different states. Despite its waning popularity, states are unlikely to ever support a constitutional amendment abolishing the electoral college.
The framers of the United States Constitution were wary of direct elections. Senators were originally chosen by state legislatures, and many of the authors of the Constitution did not want citizens to directly decide the presidential election. Much of their fear was based on a lack of trust in voters. With an electoral college, educated representatives could vote for a preferred candidate if someone they did not approve of was chosen. Through the years, however, most states have passed laws requiring electoral voters to cast their votes in accordance with who the states' citizens voted for.
Most voters now support eliminating the electoral college due to its antiquated nature. In addition, many voters dislike that fact that a vote in Florida, where elections tend to be close, matters more than a vote in a state where the race is not close. George W. Bush famously won the 2000 election despite losing the popular vote, and he almost lost the 2004 election despite having a fairly large national lead. Had John Kerry received just 30,000 more votes in Ohio, he would have been elected president.