why don't you set the stage for us, mr. foner, and what is birthright citizenship? >> well, in a nutshell, this is the principle that any person born in the united states, regardless of the status of their parents, their ancestors, regardless of their race, gender, religion, any other category, is a citizen of the united states just by the virtue of being boerch here. of course you can also become a citizen by naturalization if you're an immigrant. but the important point is this was not a principle that goes all the way back to the institution constitution. it was really implemented or institutionalized in the aftermath of the civil war and the 14th amendment which wrote it into the constitution. first clause of the 14th amendment says explicitly any person born in the united states with one or two minor extensions, particularly native americans who at that time were thought to be citizens of their own sovereignties, but any person born in the united states is a citizen. and as i said, this was not necessarily the case before the civil war. the most dramatic exampl