I have communicated with high schoolers from across the U.S., a few of them, and an unfair sampling since I come into contact with them in political forums discussing issues of the day, and while most of them are liberal - that can be understood. They are only products of their education. A few of them come out of high school hard core conservatives and pro-military.
The trend is for many of those high schoolers to become conservative at some point after graduation. And facing a determined enemy is often a very convincing force for conversion from liberal to conservative.
Our high schoolers are very conservative (more so than I am in some ways); they are pro-military but they are anti-draft.