I've seen several resources for bringing the election into the classroom over the last few weeks. Here are some of what I thought were most kid-friendly:
This unit from Teachers Pay Teachers has something that could be adapted for every grade level. Click the link to download it.
Gallopade has an Elections for Kids site:
Scholastic also has an Election 2012 site with information and games.
I thought this game in particular on Scholastic was interesting for 3rd or 4th grade. You are a "party" and are trying to get the 270+ electoral votes needed to win the election, and you choose which states you are going to "win". Of course as I was playing I was thinking about the population of each state, so it might be a good way to put the electoral college in perspective for students. Maybe play it as a whole class and generate a discussion!
PBS Kids also has The Democracy Project with activities.
How about just taking a tour of the White House?