In 1970, Nixon convinced Bush to relinquish his House seat to again run for the Senate against Ralph Yarborough, a fierce Nixon critic. In the Republican primary, Bush easily defeated conservative Robert J. Morris, by a margin of 87.6 percent to 12.4 percent. However, former Congressman Lloyd Bentsen, a more moderate Democrat and native of Mission, Texas, defeated Yarborough in the Democratic primary. Yarborough then endorsed Bentsen, who defeated Bush.
Amidst the Watergate scandal, Nixon asked Bush to become chairman of the Republican National Committee in 1973. Bush accepted, and held this position when the popularity of both Nixon and the Republican Party plummeted. He defended Nixon steadfastly, but later as Nixon's complicity became clear, Bush focused more on defending the Republican Party, while still maintaining loyalty to Nixon. As chairman, Bush formally requested that Nixon eventually resign for the good of the Republican party. Nixon did this on August 9, 1974; Bush noted in his diary that "There was an aura of sadness, like somebody died... The [resignation] speech was vintage Nixon — a kick or two at the press — enormous strains. One couldn't help but look at the family and the whole thing and think of his accomplishments and then think of the shame..
. [ Ford's swearing-in offered] indeed a new spirit, a new lift.
After Ford's accession to the presidency, Bush was under serious consideration for being nominated as Vice President. Senator Barry Goldwater of Arizona declined to be considered and endorsed Bush, who, along with his supporters, reportedly mounted an internal campaign to get a nomination.Ford eventually narrowed his list to Nelson Rockefeller and Bush. However, White House Chief of Staff Donald Rumsfeld reportedly preferred Rockefeller over Bush. Rockefeller was finally named and confirmed.
In 1976, Ford brought Bush back to Washington to become Director of Central Intelligence. He served in this role for 357 days, from January 30, 1976 to January 20, 1977. The CIA had been rocked by a series of revelations, including those based on investigations by Senator Frank Church's Committee regarding illegal and unauthorized activities by the CIA, and Bush was credited with helping to restore the agency's morale. In his capacity as DCI, Bush gave national security briefings to Jimmy Carter both as a Presidential candidate and as President-elect, and discussed the possibility of remaining in that position in a Carter administration but it was not to be.