First of all, law schools like to see candidates with science/math/engineering backgrounds. Obviously, it's not a requirement (there really isn't any specifically undergrad course requirement for law school), but folks who have such courses bring a different -- and good -- perspective to looking at legal issues. So, taking such courses would definitely not be a "waste" for law school and could be a benefit by making you stand out from the thousands of poly sci majors applying to law school each year. Also, I would find it hard to believe that a law school would ding you too much for a B or even a C in a hard core math/science course if your other grades are all excellent.
If you plan to apply to USNA -- and especially as a college reapplicant -- you really must take at least some of the plebe courses. USNA wants to see how well you do in those courses. If you get As and Bs, great. If you don't, it suggests you may struggle at USNA.
So, as the others above have said, it comes down to whether you want to be competitive for USNA or you want to go to law school (now). If you want to have a shot at USNA, you need to take at least two of the following: calc, chem w/lab, physics w/lab. If you don't do that, then --being brutally honest -- it's really not worth your time and effort to reapply.
One other point, which you probably know. You can't attend law school directly out of USNA and, as a USNA grad, it's VERY, VERY hard to attend law school while in the USN. So, if your true desire is law school, either go now or (better yet) do something else for a few years after college and then go to law school. Based on personal and anecdotal experience, those who do something else first typically "enjoy" law school more than those who go straight through from college.