On August 10 , just two weeks prior to the convention opening , South Dakota Senator George McGovern entered the race , casting himself as the standard-bearer of the Robert Kennedy legacy . As the 1968 Democratic National Convention started , Humphrey stated that he had more than enough delegates to secure the nomination , but commentators questioned the campaign 's ability to hold on to the delegates . The Texas delegation announced frustration at the McCarthy campaign 's attempts to change procedures , and declared that they might renominate President Johnson as a result . Observers noted that Humphrey 's delegates were supporters of Johnson , and could follow suit . Meanwhile , protests and sleep-ins were held in the streets and parks of Chicago , forcing Mayor Richard J. Daley to order federal troops into the city . Eventually , 6,000 federal troops and 18,000 Illinois National Guardsmen were outside the convention , defending the premises . A televised debate was held featuring Humphrey , McCarthy and McGovern . Humphrey hoped to unite the party during the debate , affirming his support for peace in Vietnam , but his challengers were received better by the crowd , drawing more applause
1968 Democratic National Convention
1968 Democratic National Convention
Hubert Humphrey 1968 presidential campaign