Richard, I fundamentally disagree with you that there is such a thing as a hispanic 'culture'. Culture is defined as "The predominating attitudes and behavior that characterize the functioning of a group or organization."
http://education.yahoo.com/reference/dictionary/entry/culture

IMHO, to try, at this date, to redefine them from being a race of people is pointless even if that is a designation assigned by North Americans in the United States. [By the way, isn't North America composed of more than just the United States? Why assume it was the United States that defined these hispanic peoples as hispanics? Is it possible that some other country first came up with the designation?]

You said "So if we have to use the white American convention of race then Puerto Ricans are some of them white and some of them Black.........." Remember, the hispanic firefighter in the New Haven case was given a racial designation of 'white'.