Actually, I will say this for the law: When you have a JD, and you speak about something, people listen. Prior to my graduation, if I called a local housing authority and said, "Someone told me that one of the property managers will reduce the rents of the tenants if they let him grope them" they would write me off as another baseless complaint.
If I called them up now and made the same report, they would jump.
If I call up a housing authority and recommend they make their contracts with landlords more stringent--any foreclosure breaches the contract and immediately affords the tenant the opportunity to move--they are very interested in implementing it.
You have a lot of say. You have a scary amount of power. You also have bills and an unsupportive office environment that can (and often will) toll your emotional and physical health, as well as your relationships. (I am not the only one this has happened to--I could write a book of names of other NF lawyers who fit this profile.)
Last April-mid-July there were times I thought I would wind up in a mental health ward from a nervous breakdown. One of my friends lost 40 pounds from the stress--went from slightly heavy-set to skin and bones. Both of our relationships went on the spritz. Another coworker who finally left my office--she was so severely depressed for months and months that she only slept when not working (despite two kids and a husband).
There's much to do. But I think there are other ways to accomplish social good as well. Social work is a huge thing, you can really, REALLY directly impact the lives of so many. (I thank God for, and keep close relationships with the social workers to whom I refer my clients. I always know my clients are going into good hands, ones that will help them change their lives for the better.) Again, research in the area of poverty--the research that exists I believe is biased by politics, especially the housing research. This researh plays a big part into the decisions poverty law offices make regarding impact litigation.
Don't get me wrong--there is a need for INFJs in teh legal profession. But that is my selfishness speaking. My heart would say to you (as if you were me, 4 years ago), you would probably be much happier elsewhere, and you would still feel fulfilled.