What Student Congress needs is a mandatory service requirement.Think of it as jury duty. The student body president could randomly draw personal identification numbers each week, a la ticket distribution. Then the students whose numbers were chosen would have to serve on Congress that week.
They would have to go to the meeting, fall asleep, pick their noses on camera and pass a resolution that would profoundly affect the death penalty in Iraq. They would then be free to go and be exempt for another year. And if they didn't show up for their duty? Unlike with real jury duty, it wouldn't be punishable, because it's getting obvious that even the people who are actually elected to Student Congress don't always bother to go to meetings.
On second thought, it doesn't look as though mandatory Student Congress service would actually change the face of the organization that much. But if year after year it has trouble filling its ranks, perhaps members should consider changing the way it operates.
For example, there are districts in which no one runs and districts in which people run opposed. While no one is willing to fill the seats in certain districts, there are people who want to be in Congress who cannot be because they lose. There's no compelling reason for Student Congress representatives to represent geographical districts. Yes, different parts of campus and off-campus housing locations have different needs and interests, but as students our needs and interests will remain fairly constant.
Congress should consider a system that allows anyone who is willing to serve to be in Congress by letting people who don't live in a district represent that district. It might not fill all the seats, but it would probably do more than continually holding special elections.