Actually, no, as far as i know nobody has formally brought any complaints to the school board. There's one person who works in the district who is native american who claims to be offended by it, but other than that, it's mostly all white people bringing the complaints--we actually have the official OK from the local indian groups as a whole, and back when we had an actual school mascot on the field (they've long since taken that away) it was actually a native american person in the suit, not some white kid trying to make a mockery of indians.
Really, the only support they have for it is that last year, 72% of people who answered a voluntary survey during lunch said they wanted a mascot--note that the survey made no mention that a "raider" mascot was out of the question. This survey (in which less than 1/6 of the school took) is the sole basis for the mascot change.
And for those of you who don't understand what's racially offensive about the raiders, the complaint is that it gives everyone the idea that all native american people are raiding, pillaging, senseless brutes. i think anyone with a brain bigger than the size of a grain of rice could see through a name like that--we don't even have any arrowheads/feathers/anything indian associated with anything except our school's "coat of arms" which has a picture of an indian with a mo-hawk. unless they're offended by that one picture, there's really no other place where the term "raiders" is anything more than a name, unless you're paranoid enough to analyze the school's history when we may have been a tad less tactful, but those days are long gone for crying out loud!