Arthur questions this idea when he looks back on his life, and the mistakes he has made. He cannot see how millions of people could allow one leader to force them into doing things they would not normally do on their own. He tries to figure out how the one leader's ideas could win against the million others. Arthur then realizes that the leader must have possesed something that appealed to the people. Something must had stood out in the begining for the people to put all of their trust into one person.
I agree with the latter. Think of Americans and President Bush, for example. How did he get into office when almost everyone has something negative to say about him? The answer is simple: the majority of people elected him into office. He must have had something that appealed to the people. Americans were not looking for change at the time, and stuck with what they knew.
Now four years later, in a time of need, U.S. citizens voted for "change" and chose Barack Obama. No one knows for sure if he'll be a good or bad president. He could be one of the greatest presidents Americans have ever seen, or one of the worst in history. But his speeches were appealing, and his idea of change turned voters onto him, causing him to win by a landslide.
Leaders don't just happen. They need the people to help them achieve their power. If a leader does not live up to one's expectations, don't blame the leader, blame the people for giving them their power.