You getting sworn in tomorrow? Congrats I did student government at my school for a bit. We could never fill all the senate seats though lol. I would say it is fine but dress more conservatively if you want to be cautious. Maybe go longer at the first meeting and see what others do.
I'd say go for knee-length pencil skirt or dress pants. A mid-thigh pencil skirt COULD be ok, depending on many other things, but I wouldn't take the risk of being unappropriate for an important event like this. I think the dress pants are a sure thing, but knee-length skirt is possible too. Of course, no cleavage or over-tight clothes either :)
i would say wear dress pants it does seem a bit short but if your in doubt do what crazynkinky said.
I always find that if I'm wondering if a skirt is appropriate then it probably isn't. I'd probably go for a longer skirt or the dress pants.
Most employers will tell you skirts need to be knee length. I'm not sure what attending a student government meeting entails, but if you are trying to look professional I would go for the pants or a longer skirt.