The principal was very nice but said he really needs a remedial math club and could I do that instead???
A "remedial math club" is called "after-school tutoring" and the school is mandated under NCLB to provide it to students who are falling behind. No way that this should be considered your responsibility and no way that it should substitute for a competitive math club for student who are actually interested in math. Of course, all students who
are actually interested in and excited about learning problem-solving strategies and techniques should be encouraged to attend the competition-focused math club, even if they don't seem likely to win any prizes.