There was a post similar to yours a day ago: http://talk.collegeconfidential.com/college-search-selection/2024787-good-political-science-schools.html#latest
On the topic of Northwestern, it is a well-respected and definitely a very competitive school. With that being said, one can’t really “chance” you considering and assuming you don’t have an SAT score and PSAT score yet. Your ECs also happen to be on the slightly weak side.
But don’t give up! You still have alot of time to improve! Your GPA doesn’t seem like it’s critically bad, and your “extra thing” seems to help.
Do note that price is also an important factor here, as well as financial aid.
Other lists of schools you should look at is in the link provided above.
Good luck! 