Well, lets look at this objectively.
Young people in this country are indoctrinated by the leftist propaganda machine that exists in virtually every institution of higher learning in the United States ( not to mention the brainwashing done by our nations public schools). Uninsured people think that they are now magically going to get legitimate medical coverage. Non-Whites ( And I will bet you anything non-whites is really just blacks and hispanics) make up the lower spectrum of poverty in this country, almost uniformly voted for Obama and favor Obama even though they have no idea what his policies are.
So, all in all I think that these three groups being in favor of Obamacare is not a shock by any means.