Donna,
Hopefully, it's just that it's a crazy time of year and the person has been extremely busy. To add to gjcoram's questions about the nature of your messages, did you reference a specific meeting? Maybe if you set a specific purpose or time (i.e. we are meeting at 7pm on Thursday to discuss the finances for the fall) they will respond.
... did you have anyone else interested in the position?
Was this person returning your calls before the election?
Has this person been out of town? If you sit back and think about the messages you left, were they friendly? (Hi, congrats on winning, I'd love to sit down and chat with you about how to get up to speed.) Or were they accusatory? (Hey, you missed the election, are you serious about being treasurer? You'd better get cracking!)
Can you catch this person in person at school -- pick-up or drop-off?