<Tr> <Th> College graduates </Th> <Td> 21 </Td> <Td> 79 </Td> </Tr> <Tr> <Th> High school graduates </Th> <Td> 9 </Td> <Td> 91 </Td> </Tr> <Tr> <Th> High school nongraduates </Th> <Td> 5 </Td> <Td> 95 </Td> </Tr> <Tr> <Td_colspan="100"> GALLUP, OCT. 29 - NOV. 2, 1965 </Td> </Tr>

4. public opinion about the vietnam war began to turn increasingly negative after which event(s)