I give you credit for giving calculus a shot. Lord knows I wouldn’t have the courage to do that. I wouldn’t stress over the C much, if I were you.
In my view, part of navigating college is knowing what classes to take, and bearing in mind the ones to avoid. From what I’ve read, there seems to be some kind of consensus that Calculus II is one of the most difficult math classes one will ever take.
Since you’re a political science major, I see no reason to burden yourself with such a course. Achieving a B in Caluclus II will have no beneficial bearing on your admission status. But as said above, a C could most certainly jeopardize your chances.
I do understand why you feel like you must take Caluclus II. But you don’t have anything to prove. You have a stellar GPA. Taking such a difficult class that is completely unnecessary for your major doesn’t say much besides you’re willing to challenge yourself. But I think A’s look a lot better than any perceived struggle.