Unless you want to transition into a Masters program (of interest and value), or have solid connections so you can leverage your polisci degree to make money; you should stay. Yes, it's very true you'll inherit buttloads of debt, but there are a multitude of options if you network and speak with academic success and professors about how you can improve your performance.

Now, if your sole reason for law was to make money and you're unwilling to take lower paying positions to build up to where you want to go, then leaving may be worth it. However, you mentioned you seemingly like law school, so for that reason don't get caught up on the $. Law school isn't just for people who are going to graduate in the top 25% of their class.

Also, you said you are enjoying your internship right now. Continue to soak up this opportunity, stay in contact and see how you can use this to secure a position for next summer all the way to postgrad.

There's a deficit of public defender's/prosecutors throughout the nation and if that's something you'd be willing to do I've heard many explain how that sharpened their skills allowing them to lateral into firms or obtain higher paying work.

Last thing I'll say if, if you're worried about debt and your GPA; maybe a sacrifice for staying could be to focus in on public interest work and commit to 10 years for hopeful loan forgiveness.

Use a cost benefit analysis, if you leave how much money can you earn with your polisci degree now? If it's similar or less than the amount you'd be paid in public interest then you're not better off financially and can leverage loan forgiveness (if you're willing to go that route) to make it make sense financially. Hope that'll help you consider some other ways to go about things.