By 1968, President Lyndon Baines Johnson was finally done in by his "credibility gap" -- the growing abyss between what he said about, and what was actually happening inside, Vietnam.
"Modified limited hangout" and "inoperative" were infamous euphemisms that Nixon administration officials used to mask lies about the Watergate scandal. After a while, few believed any of the initial Reagan administration disavowals that it was not trading "arms for hostages" in the Iran-Contra scandal.
George H.W. Bush thundered during his campaign to "read my lips: no new taxes," only to agree later to raise them. Bill Clinton's infamous assertion that "I did not have sexual relations with that woman" was followed by proof that he did just that with Monica Lewinsky.
The George W. Bush administration warned the nation about stockpiles of weapons of mass destruction in Iraq and never quite recovered its credibility after the WMD were not found. No one believed Bush when he told incompetent FEMA Deputy Director Michael Brown that in the midst of the Katrina mess he was doing a "heck of a job."
Yet the distortions and lack of credibility of the Obama administration have matched and now trumped those of his predecessors. The public may have long ago forgotten that Obama did not close down Guantanamo as promised, or cut the deficit in half by the end of his first term, or stop the revolving door of lobbyists coming in and out of the executive branch.
The public may even have forgiven the president when the stimulus bill never lowered unemployment as promised, or when his misleading boasts about vast increases in oil and gas production came to fruition despite, not because, of his efforts.
But the distortions and broken promises have now become so frequent that many at home and abroad are finally tuning out the president. Almost nothing promised about the Affordable Care Act is proving true. Contrary to presidential assurances, Obamacare has not lowered premiums or deductibles. It will not reduce the deficit or improve business competitiveness. It really will alter existing health plans and in some cases lead to their cancellation. Signing up is certainly not as easy buying something online on Amazon.
Two considerations often turn these presidential ethical lapses into political disasters. Unfortunately, both apply to the present administration.