The Constitution starts with "we the people of the United States." In other words, it begins by defining who it applies to, that is citizens. The content therein does not apply to any illegal invader. Imagine if during WW II the Japanese had invaded mainland USA as many Americans had feared they would. Would a Japanese soldier be covered by the Constitution? Of course fucking not! The same is true of an illegal invader who has invaded by sneaking into the country. Such a person has no rights under the Constitution.