There are lots of good suggestions here. You are a strong candidate and will do well. Some of the schools, though, are extremely competitive and must deny admission to many very qualified students. I’d suggest making sure you find some schools where you would feel more assured of admission, would be happy attending, and can afford. Schools under 20% can be difficult and unpredictable for everyone. I would think you would have a good chance at most of the schools where you’d be looking that have over a 30-40% acceptance rate. All these numbers are just approximations.
I’m not sure how familiar you are with the US admissions process. A unique feature, I think, is the early rounds of applications. Most schools have Early Action (EA), Early Decision (ED), or both. There are some exceptions but generally students can only apply ED to one school, and they must attend if accepted (just a very few exceptions, pretty much financial only). So the decision to apply ED is a huge one. Deadlines are generally mid-October to December. Students can apply to as many EA schools as they want and don’t have to attend. They can apply to one ED and also as many EA as they want.
It depends on schools, but often there is an advantage in applying early, especially ED. Schools like ED applicants because the school is their first choice and they will definitely come. Some of the most competitive schools will accept 20% or more of applicants ED and less than 10% in the regular application round. You can find the numbers for a particular school. So if you have a school you love, and it is very competitive, you might consider ED, which will be coming up in just a few months.
I love Denison; it is in a relatively small town. Same with Hamilton. Macalester is an excellent choice for international students interested in politics (very, very cold). Wellesley would be a good choice if you are considering an all women’s school. Very beautiful campus in a quaint suburban town near Boston. The woman I mentioned before had the same interests as you and got some fantastic internships. You might look at Tufts and Boston College as well. Both are in the near Boston suburbs. Tufts, especially, is strong in political science and is home to the Fletcher School, a top grad school for international affairs. It has very competitive admissions. Holy Cross in Worcester (about an hour or so by train from Boston ) is also outstanding in political science.
You might also look at the College of William and Mary in Virginia. It has about 6000 undergrads. It is usually listed with UVA, UNC, Cal, and Michigan as a top public university. Unlike those others (large state flagships), it’s basically a large LAC. Campus is beautiful, and the weather is nice. Secretary of Defense Robert Gates, FBI Director James Comey, and State Department spokesperson Jen Psaki (all formerly in those positions) are William and Mary alums.
Someone mentioned Amherst, and I had mentioned the five-school consortium. That might be something for you to look at, especially Smith, Mount Holyoke, and Amherst. Smith is in Northampton, which I love as a small college town. The school and town have more of a funky, hippie vibe, and Amherst is more preppy, conservative, if one suits you more than the other. I think Mount Holyoke is more in the middle among those three schools. Amherst would be the most competitive.