All seriousness aside, I don't think there is a single academic discipline that prepares you comprehensively for political life.
A JD is certainly a good thing to have, mostly IMO for the critical thinking and ability to read and interpret. As far as any specific knowledge of the law I think it's like other degrees. You get introduce to topics and until you actually go out and practice, you don't really have a thorough understanding.
With lawyers, engineers, doctors, techies, they too often get caught up in their own lingo and can't related well to people outside their sphere. I posted once before about engineers will correct someone for using the word velocity instead of speed.
I had several government clients. Most of them sorely lacked business acumen.
If they ever crafted a wider bachelors degree that included the classics arts curriculum augments with some poly sci, international relations, accounting finance, science, engineering, and law, it would be a home run.
The problem is to fit all that into 120 credits.
The thing that no degree will ever teach is the overall political process to get things done.
Idea > groundwork > > relationships > consensus building > formal construction > votes > adopted law or policy
IMO, politics and government has become less bout governance and stewardship and more about theater, elections, public relations, image, and of course power.