If you have room you might want to diversity wise. I put campaigns as my first activity for the common app, but during the fall on-season I'm working 15-20 hours a week and I'm still involved with campaigns in the early stages in off years.
You might want to include the campaigns if you do put it down. The current chair of one of the parties in Colorado told me a few years ago that colleges do call up him (Even when he was a major county chair at the time not state) to see if what students put down was true because often times kids embellish their roles when they really just made some phone calls.
I know I'm walking on a thin line with all but one campaign I've volunteered or worked on coming from the same party and listing them down...but hey I want to be a political science major (maybe
) so how else do I show I'm committed? haha