A law degree is the road to nothing more than an education in how to justify billing clients for your services and/or justify taking a contingency. If you want to learn "about the law," buy a book "on the law." Law firms are nothing but a dressed up Wal-Mart, McDonald's, or H&R Block -- a law degree is nothing but a ticket to work at a law firm.
I attended a T25 law school and now work at a large regional firm. Signing the promissory notes, to me, were nothing but a formality because I knew, with 100% certainty, that I wanted to be an attorney. I am now an attorney and love it. There are things about my job that other people would hate if they did not have the right attitude or skills, and I think those things are apparent to even someone who is a pre-1L.
If you have any doubts, I honestly would not attend. While it is virtually certain that you will get a biglaw job coming out of a top 10 law school and will be able to pay back the $200,000 in debt, the truth is that you will be sitting in New York City or D.C. in a 150 square foot office (if in Manhattan, shared with another new associate) managing a discovery project where contract attorneys are going through thousands of pages of electronic records for some mega-company. They will go through thousands of pages and tag what might be even remotely relevant. Then it will be your job to go through the hundreds of pages they tag every week and write a memo on the value of the evidence or the possible detriment of that evidence.
Otherwise, you might get to work on some motion that will have little if any impact on a case.
The friends I have who went to biglaw right now, a year out of law school, sit on Facebook all day (I can see them on the "Chat" function) and are at work from 9am to 9pm. They are so disillusioned at this point that their status updates expressly complain about how bored they are, how they don't get any billable work and are just doing busy work, etc., etc., etc. It seems like they are literally TRYING to get fired but don't have the balls to quit.
You can, of course, always shoot for a regional job at larger firm, but not biglaw, near where you grew up and take less of a salary. I can tell you based on my personal experience that it is great. I work about 50 hours a week (though, when I am here, I am working my ass off usually), go to hearings, draft and file motions, complaints, answers, etc. on my own for five and six figure cases, attend hearings, even argue motions, and so on, and I have not been admitted for even a year.
With that said, though, again, those things I just listed entail a lot of work that most people would not be cut out to do. It is tedious, requires great focus to be done correctly, and, usually, nobody really recognizes it when you do a good job. It's up to you. but given what you posted, I would apply to London School of Economics (a third of the cost, if that, and looks great on a "Policy" resume) or to a top 10 PhD program in the area of policy that interests you (again, this will cost a third or less of what the JD costs if you do asst. research etc., and will get you the kind of job you probably want at an institute, university, etc.).