had greatly escalated U.S. commitment that by late 1967, over 500,000 American soldiers were fighting in Vietnam. Draftees made up 42 percent of the military in Vietnam, but suffered 58% of the casualties, as nearly 1000 Americans a month were killed, and many more were injured. But resistance to the war rose as success seemed ever out of reach. The national news media began to focus on the high costs and ambiguous results of escalation, despite Johnson's repeated efforts to downplay the seriousness of the situation. In early January 1968, Secretary of Defense Robert McNamara said the war would be winding down, claiming that the North Vietnamese were losing their will to fight. But, shortly thereafter, the North Vietnamese launched the Tet Offensive, in which they and Communist forces of Vietcong undertook simultaneous attacks on all government strongholds across South Vietnam. Though the uprising ended in a U.S. military victory, the scale of the Tet offensive led many Americans to question whether the war could be "won", or was worth the costs to the U.S. In addition, voters began to mistrust the government's assessment and reporting of the war effort. The Pentagon called for sending several hundred thousand more soldiers to Vietnam. Johnson's approval ratings fell below 35%. The Secret Service refused to let the president visit American colleges and universities, and prevented him from appearing at the 1968 Democratic National Convention in Chicago, because it could not guarantee his safety. Republican Party nomination Other major candidates The following candidates were frequently interviewed by major broadcast networks, were listed in publicly published national polls, or ran a campaign that extended beyond their flying home delegation in the case of favorite sons. Nixon received 1,679,443 votes''' in the primaries. Primaries The front-runner for the Republican nomination was former Vice President Richard Nixon, who formally began campaigning in January 1968. Nixon had worked tirelessly behind the scenes and was instrumental in Republican gains in Congress and governorships in the 1966 midterm elections. Thus, the party machinery and many of the new congressmen and governors supported him. Still, there was wariness in the Republican ranks over Nixon, who had lost the 1960 election to John F. Kennedy and then lost the 1962 California gubernatorial election. Some hoped a more "electable" candidate would emerge. The story of the 1968 Republican primary campaign and nomination may be seen as one Nixon opponent after another entering