George H.W. Bush 1989-93
George HW Bush served, along with the 'Gang of Four' - PNAC signatory Donald Rumsfeld, PNAC signatory Richard Cheney, Frank Carlucci, and PNAC signatory Caspar Weinberger, in the Nixon Administration.
Before that, George HW Bush was involved in the following nefarious activities:
[In the mid-1960s George H.W. Bush] defended the House Committee on Unamerican Activities [HUAC] against the demonstrations organized by James Foreman and SNCC, commiserated with a State Department official who had been branded a fascist at Iowa State, and went on to assail the Berkeley "filthy speech" movement. As an example of the "pure naivete" of civil rights leaders, he cited Coretta Scott King who "managed to link global peace and civil rights, somehow managed to tie these two things together philosophically" -- which Bush professed not to fathom. "If we can be non-violent in Selma, why can't we be non-violent in Viet Nam," Ossie Davis had said, and Bush proposed he be awarded the "green Wiener" for his "absurd theory," for "what's got to be the fuzziest thinking of the year."
The resident ideologue in the Reagan Whitehouse was PNAC signatoryFrancis Fukuyama, disciple of (pop social commentator) Allan Bloom and odd-ball philosopher Leo Strauss, darling of the neocon crowd:
[Bush's] fatuous delusions of grandeur were duly projected upon the plane of the philosophy of history by an official of the Bush Administration, Francis Fukuyama, the Deputy Director of the State Department Policy Planning Staff, the old haunt of Harrimanites like Paul Nitze and George Kennan. In the winter of 1989, during Bush's first hundred days in office, Fukuyama delivered a lecture to the Olin Foundation which was later published in The National Interestquarterly under the title of "The End of History?" Imperial administrator Fukuyama had studied under the reactionary elitist Allan Bloom. ... Fukayama was a follower of Hegel in the interpetation of the French postwar neo-Hegelian Alexandre Kojeve. 
Fukuyama is now bio-ethics advisor in the George W Bush Administration.
Another disciple of Strauss and Bloom is current Deputy Secretary of Defense and PNAC signatory Paul Wolfowitz. He was Undersecretary of Defense for Policy under George HW Bush. In 1992, in the final days of that administration, he wrote a document called 'Defense Planning Guidance'. This document was not only a precursor to PNAC (200),  it was a tool for undermining Clinton foreign policy (see Clinton/TeamB) in much the same way that Ford's 'Team B', commissioned by George HW Bush (then-Director of the CIA under Reagan), undermined Carter's foreign policy. Wolfowitz was a member of 'Team B'(see: Ford/TeamB) along with Paul Nitze, his mentor. Both incidents were modeled on the way that Nitze had commandeered Truman foreign policy by writing National Security Memorandum # 68 (NSC-68) in 1950 (see Truman/Nitze).
Many shuddered upon hearing George H. W. Bush announce the advent of 'A New World Order' in his now infamous State of the Union address in January, 1991  because that phrase was so reminiscent of Hitler's 'New Order'.  Was this just a coincidence? Professor Boyle of the Albany Law School apparently did not think so when he wrote [in 1992]:
Today, the government in the United States of America constitutes an international criminal conspiracy under the NurembergCharter, Judgment and Principles, that is legally identical to the Nazi government in World War II Germany. The Defendants' wanton extermination of approximately 250,000 People in Iraq provides definite proof of the validity of this Nuremberg Proposition for the entire world to see. Indeed, Defendant Bush's so-called New World Order sounds and looks strikingly similar to the New Order proclaimed by Adolph Hitler over fifty years ago. You do not build a real New World Order with stealth bombers, Abrams tanks, and tomahawk cruise missiles. For their own good and the good of all humanity, the American People must condemn and repudiate Defendant Bush and his grotesque vision of a New World Order that is constructed upon warfare, bloodshed, violence and criminality. Perhaps the similarities between Nazism and Bushism are not merely the product of feverish brains of a feather flocking together. "The Bush Gang" by Robert Lederman (written in January 2001), provides a very interesting bit of history that goes a long way in explaining the relationship:
As promised, George W. Bush has recruited competent and experienced advisors. Despite their seeming diversity, however, they have a common denominator. The America they reflect is the oil, pharmaceutical, armament, Wall Street and eugenics interests long associated with the Bush family.Prescott Bush was George HW Bush's father.
Prescott’s dreams of riches began to crumble in the summer of 1942. The New York Tribune had discovered and written on the Bush-Thyssen connection. The Tribune hung the moniker of “Hitler’s Angel” on Bush. On October 20, 1942, after investigation by the US government, Vesting Order 248 was executed. The order stated…( a) That the property described as follows:With that, Prescott Bush lost his power in the Union Banking Corporation. But the story, and the audacity, of Prescott Bush do not end here. .... " 
More on this aspect of the Bush family can be found in "George Bush: The Unauthorized Biography" - by Webster G. Trpley & Anton Chaitkin. Its on the web, in its entirety, at http://www.tarpley.net/bushb.htm. Also see Warren Harding/Prescott, FDR/Prescott, Gehlen/Prescott, Lovett/Prescott, Eisenhower/Prescott, JFK/Prescott, PNAC Signatories/Prescott
The Rest of the Iceberg