I haven't ever been in your situation, but I do have a few ideas.
First of all, I think that you should start by finding a teacher or two that will support you. Personally talk to them and explain what everything is. Make them a little knowledgeable on the subject. (It would probably help your cause a lot if you could find math/science teachers.)
Then you move to the school board and set meeting dates where you can bring in the teachers and other people that might give some positive influence.
The most important part, through doing all of this, I believe, is to make them understand what this means to YOU. There is no better way than being honest, and using personal stories, from you or other people, and give some examples of students who have gone on and have earned their way to jobs in the math/science/engineering/technology fields.
I know that visual aids would help a lot too. Pictures of robots, highlighting the benefits, and also showing the other skills that students would learn, such as being able to interact in a mature way with adults and communicate their ideas and thoughts clearly and confidently.
Visual aids are a key. If our team went to our CDR (critical design and review) and simply talked to the engineers and mentors about our robot and showed them no pictures and indicated no abilities or thoughts that we had, we wouldn't gain any input or feel that going through this process was valuable. The same applies in your position. You can't simply speak; you have to demonstrate.
Just my input, and good luck in your endeavors.
