Nixon established himself as the clear front-runner after a series of early primary victories. Governor Ronald Reagan of California was the first choice for party conservatives and Governor Nelson Rockefeller of New York held the same position for those at the other end of the political spectrum within the party. At the August 1968 Republican National Convention in Miami Beach, Florida, Reagan and Rockefeller discussed joining forces in a stop-Nixon movement, but the two were too far apart politically for such a coalition to take shape. Nixon secured the nomination on the first ballot. He selected Maryland governor Spiro Agnew as his running mate, in order to appeal to both Northern moderates and Southerners disaffected with the Democrats.
At the start of 1968, most Democrats expected that President Lyndon B. Johnson would be re-nominated. But when Senator Eugene McCarthy, entered the campaign late in November to be the voice for those in the party opposed to Johnson's Vietnam policies, the political calculus changed. McCarthy narrowly lost to Johnson in the first Democratic Party primary on March 12 in New Hampshire, winning 42% of the vote to Johnson's 49%. This convinced Senator Robert F. Kennedy of New York to enter the race. Two weeks later, Johnson surprised the nation by announcing that he would not seek a second term. In the weeks that followed, momentum shifted toward Kennedy. Vice President Hubert Humphrey declared his own candidacy, becoming the establishment candidate. When Kennedy was assassinated in June 1968, the stage was set for Humphrey to win the presidential nomination at the August 1968 Democratic National Convention in Chicago. Outside the convention hall, thousands of antiwar activists clashed violently with police in a scene broadcast to the world in a scene that hurt the Humphrey campaign.
The assassinations of Kennedy and Martin Luther King, Jr., combined with disaffection towards the Vietnam War, the disturbances at the Democratic National Convention, and a series of city riots in various cities, made 1968 a tumultuous year. Nixon portrayed himself as a candidate of stability in a time of national unrest. He called upon the "silent majority" of Americans who longed for more traditional times. He promised "peace with honor" in the Vietnam War. Humphrey's polling position improved in the final weeks of the campaign as he finally distanced himself from Johnson's Vietnam policies. Johnson sought to conclude a peace agreement with North Vietnam in the week before the election, but Nixon supporter Anna Chennault convinced the leaders of South Vietnam to wait until after the election. The collapse of peace talks shortly before the election halted Humphrey's momentum. Nixon defeated Humphrey by a margin 43.4% to 42.7% of the popular vote. In the Electoral College, Nixonwon 301 votes to Humphrey’s 191 and 46 for third party candidate George Wallace. Despite Nixon's victory, Republicans failed to win control of either the House or the Senate in the concurrent congressional elections.
For the major decisions of his presidency, Nixon relied on the Executive Office of the President rather than his Cabinet. His Chief of Staff H. R. Haldeman and his domestic adviser John Ehrlichman became his two most influential staff members. Nixon's interaction with other staff members was conducted through Haldeman.
Cabinet members were relegated to a lesser position of influence in the Nixon White House. One exception was Attorney General John N. Mitchell held sway within the White House. Mitchell had been a municipal bond lawyer, who was the director of Nixon's 1968 presidential campaign, and one of Nixon's closest personal friends. After his tenure as Attorney General, he served as director of Nixon's 1972 presidential campaign. Mitchell led the search for Supreme Court nominees. His tenure would end badly due to his involvement in the Watergate affair. Mitchell was sentenced to prison in 1977 and served 19 months after having once been known as a "law-and-order" Attorney-General.
Nixon wanted to centralize control over the intelligence agencies, but he was generally unsuccessful, in part due to pushback from FBI director J. Edgar Hoover. Rather than relying on the Republican National Committee, Nixon's re-election campaign was primarily waged through the Committee for the Re-Election of the President (CREEP), whose top leadership was composed of former White House personnel, including Mitchell.
In foreign affairs, Nixon enhanced the importance of the National Security Council, which was led by National Security Advisor Henry Kissinger. Nixon's first Secretary of State, William P. Rogers, who had once served as United States Attorney General under President Dwight D. Eisenhower. Rogers had little influence during his tenure, as Nixon placed more reliance on Kissinger's advice. In 1973, Kissinger succeeded Rogers as Secretary of State while continuing to serve as National Security Advisor.
Nixon presided over the reorganization of the Bureau of the Budget into the more powerful Office of Management and Budget. By doing so he concentrated more executive power in the White House. His first Treasury Secretary was David Kennedy, was a prominent member of the Church of Latter Day Saints who had been with the Brookings Institute and who had served on Chicago Mayor Richard J. Daley's commission for economic growth in that city. He held the post until February of 1971. In early 1971, former Democratic Governor John Connally of Texas became Secretary of the Treasury. Connally would become one of the most powerful members of the cabinet and coordinated the administration's economic policies.
With the Vietnam War continuing, Nixon chose Wisconsin Congressman Melvin Laird as his Secretary of Defense. Laird was instrumental in creating the administration's policy of withdrawing U.S. soldiers from the Vietnam War. He coined the expression "Vietnamization," referring to the process of transferring more responsibility for combat to the South Vietnamese forces. He held the post for all of Nixon's first term.
In a 1970 memo to top aides, Nixon wrote that in domestic areas other than crime, school integration, and economic issues, "I am only interested when we make a major breakthrough or have a major failure. Otherwise don't bother me." He recruited former campaign rival George Romney to serve as the Secretary of Housing and Urban Development, and Massachusetts Governor John Volpe as Secretary of Transportation. The two quickly fell out favor as Nixon attempted to cut the budgets of their respective departments.
Other initial cabinet appointees included Alabama construction executive Winton Blount as Postmaster General, Alaska Governor Wally Hickel as Secretary of the Interior, and Nebraska University Chancellor Clifford Hardin as Secretary of Agriculture. He chose Minnesota accountant and civil servant Maurice Stans as Secretary of Commerce. Stans later served as the finance chairman for the Committee to Re-elect the President. Stans was later convicted on multiple counts under the Federal Election Campaign Act that were revealed during the larger investigation into Watergate.
As Secretary of Labor Nixon chose MIT professor and former marine George P. Shultz. Schultz was later elevated to the post of Treasury Secretary in 1972 and later served as Secretary of State under Ronald Reagan. His choice for Secretary of Health, Education, and Welfare was Robert Finch, former Lieutenant Governor of California.
A month after the election, Nixon used a televised ceremony to announce his choices for the Cabinet. The nominees sat on a stage at the Shoreham Hotel, in Washington, while Nixon stood at a microphone to the side. After giving a glowing biography of each nominee, Nixon said of the group. "These are strong men, they’re compassionate men, they’re good men. I don’t want a Cabinet of yes-men." Few of the new cabinet nominees were well known and few had any sort of political profile. He appointed his old friend Herbert Klein to serve as communications director in his new Administration. Following his appointment, Klein told a group of media members: “Truth will become the hallmark of the Nixon Administration. We will be able to eliminate any possibility of a credibility gap in this Administration.”
In 1973, as the Watergate scandal came to light, Nixon accepted the resignations of Haldeman, Erlichman, and Mitchell's successor as Attorney General, Richard Kleindienst. Haldeman was succeeded by Alexander Haig, who became the dominant figure in the White House during the last months of Nixon's presidency as Nixon was consumed on the Watergate scandal that ultimately led to his resignation from office.