Pros
Friendly, intelligent co-workers. Everyone gets along, and although as an intern you're doing a lot of the grunt work, the executives do really great work for their clients overall in an exciting, fast-paced environment!
You get to watch live hearings and events and work on many different types of research projects for the partners.
Cons
As a small firm, there's a lot of things that need to get done in a short amount of time. It may be hard to keep up with some of the work (and again some of the work may be administrative) but overall it's a very rewarding experience. Being a legislative aid is a very difficult job and I have a lot of respect for the people that can keep up with the high level of stress and work-load.