nevertheless, efforts to categorize people into a racial hierarchy go back hundreds of years. whether it s five races, three races, africans and m mongoloids. there s this pseudo-racial science which tries to give a supposedly objective grounding to what is ultimately a system of prejudice. another case in 1896 shows just how arbitrary definitions of race can be in america. a man who was white by any definition, but he was considered black because maybe one black ancestor. he intentionally boarded a whites only train car in louisiana, challenging the state s separate but equal laws. the conductor came and said,
it simply, there is no basis in scientific fact or the human genetic code for the notion that skin color will be predictive of intelligence. nevertheless, efforts to categorize people into a racial hierarchy go back hundreds of years. whether it s five races, three races, africans and mongolo mongoloids as they were called. whites and caucasians as they were called. there is always this pseudo science that tries to get an objective grounding to what is ultimately a system of prejudice. the case of plessy versus ferguson in 1896 shows just how arbitrary definitions of race can be in america. a man who was white by any definition, homey plessy, but he was considered black because,
no one to vote for. reporter: the pro unionist politicians, there is a growing concern. the dup hardline stance is doing more harm than good. it doesn t mean united ireland is inevitable. but it does mean brexit could possibly be the strongest goal by unionism in 100 years. reporter: the dup unrepentant. we should start links with the rest of the united kingdom. those go back hundreds of years. and we re not going to give that up. reporter: for now the dup can breathe easy, the poll shows less than one-third of voters in the north want union with the south. even as polling south of the border of 1,200 people shows a significant majority in favor of irish unity. but all that is in the distant future. right now, the brexit end game is front and center. on friday, the irish prime
northern ireland. a sentiment we found among unionist voters. to me, in fact, one of the biggest potential threats to the union is the dup and their stance. really? there is a big sway of the middle ground in northern ireland who, quite frankly, have no one to vote for. reporter: indeed, among northern island s more moderate prounionist politicians there is a concern the gup hardline stance is doing more harm than good. it doesn t mean that a united ireland is inevitable, but it does mean that brexit could be the biggest own goal in 100 years. we have huge historic links with the rest of the united kingdom. and those go back hundreds of years and we re not going to give that up. reporter: so now the dup can breathe easy. the poll shows less than 1/3 of voters in the north want union with the south.
mary, thanks. this is cnn s breaking news coverage of hurricane irene. i m martin savidge at the cnn world headquarters in atlanta. i m keira phillips. thanks for staying with us for the hurricane coverage. a massive category 1 storm is what we re talking about, slowly churning up the east coast. it it s large, dangerous and relent areless. at least nine deaths are now blamed on this hurricane, more than 1 million customers have lost power. right now irene is closing in on ocean city, maryland. like every other beach resort along the mid-atlantic, it is just about deserted. winds have decreased slightly to 80 miles an hour but it remains a hurricane as it it pushes north toward new york. irene is especially dangerous because it s moving slowly. we ve talked about this all morning, all afternoon. it s almost certain to create a tripling storm surge. as you just heard mary mention, new york transit officials earlier today shut down the city s mass transportation system