Statesare sov-ereignentitiesin theirownright andhave theunques-tionedauthority to repel aninvasion in theirstates, made even morecritically necessarywhen the federal gov-ernment has so abject-ly failed in its responsi-bility to safeguard thenation’s borders.One of the centraltenets of our constitu-tional scheme is that,with the exception ofthe limited, enumerat-ed rights and powersgran...