This is a bad analogy.
I'd explain that voting for Class Leader is like states voting for their senators. You can also break the class into rows and have each row vote for a representative.
Now, if you told the class that each class would vote for the School Leader, and the School leader would be the person who won the vote in the most classes, would they be able to understand that?
-PJ
That's close, but that's really not addressing the Electoral College. You'd have to explain that the class would be voting for School Leader, but each class is divided into groups of boys, girls, teacher, blacks, whites, ethnic groups and each group gets to vote for School Leader. In this analogy its clear that several groups are voting several times, but that's besides the point. The point is that some classes will have more groups than other classes and is akin to some States having more people than other States. Now its pointed out that the music teacher, who has no students in class during the election, is guaranteed three votes (the teacher's vote, and a vote for boys, and girls), so does the principle, and the janitor, and a bunch of other individuals. This points out that even the least populated States have some say so in the election (compared to the classes with a large number of groups).
Then explain to the children that a smart student could campaign to all the individual teachers, and the hall monitors, the lunch ladies, principle, etc., or choose only to compaign to one or two classes with a large number of groups.
I bet the kids would get it.