<p>Yes, there are lots and lots of lawyers in those jobs (that's how Thurgood Marshall started out, and many others). Can be richly rewarding work, and many law schools forgive student loans if one enters such a field.</p>
<p>Yes--there are lawyers who practice "nonprofit law," which is largely a tax practice--helping groups get and maintain tax-exempt status, counseling them on what activities they can do and how to ask for donations, etc. Several law schools have clinics where students represent nonprofit organizations--the University of Iowa and University of Michigan are two I know of. NYU also has a center on philanthropy and the law: NYU</a> School of Law - The National Center on Philanthropy and the Law</p>
<p>If you are interested in "advocating for the underprivileged" there are many ways of doing so. You can work for a non-profit organization like the NAACP or a legal aid office, become a public defender or a prosecutor (crime victims and criminals are both disproportionately poor), work for a policy advocacy group or in a government job changing the laws, etc.</p>
<p>These jobs generally pay significantly less than private-sector jobs (it's easy to earn 4x as much at a firm) and can require long hours (though many offer shorter hours and more flexibility and predictibility than working at a firm). They are very competitive since there is little funding, and there can be a great psychological burden of helping people in crisis (and sometimes a physical one--I worked at a legal clinic in a neighborhood that had occasional drive-by shootings, and I know attorneys in the domestic violence field who have been attacked by their clients' abusers). </p>
<p>Yet, as MSUDad mentions, there are great rewards to public interest work and some schools have loan repayment (generally, the more selective the school, the better the loan repayment, but there are some notable exceptions and a lot of loopholes in many schools' plans).</p>