In 1968, O'Brien was appointed by Vice President Hubert Humphrey to serve as the national director of Humphrey's presidential campaign and, separately, by Howard Hughes to serve as Hughes' public-policy lobbyist in Washington. O'Brien was elected national chairman of the DNC in 1968 and 1970. In late 1971, the president's brother, Donald Nixon, was collecting intelligence for his brother at the time and asked John H. Meier, an adviser to Howard Hughes, about O'Brien. In 1956, Donald Nixon had borrowed $205,000 from Howard Hughes and had never repaid the loan. The loan's existence surfaced during the 1960 presidential election campaign, embarrassing Richard Nixon and becoming a political liability. According to author Donald M. Bartlett, Richard Nixon would do whatever was necessary to prevent another family embarrassment. From 1968 to 1970, Hughes withdrew nearly half a million dollars from the Texas National Bank of Commerce for contributions to both Democrats and Republicans, including presidential candidates Humphrey and Nixon. Hughes wanted Donald Nixon and Meier involved but Nixon opposed this.