请仔细看着一段话:这句话的前一句话说了:we also recognize another important limitation on the right to keep and carry arms
然后才是that limitation is fairly supported by the historical tradition of prohibiting the carrying of dangerous and unusual weapons
意思就是说:因为历史传统上禁止人们“携带”危险和特殊的武器,
所以现在的对人们“持有和携带”的限制的(法律)是符合宪法的。