How did things change so fast (in the White House)?

Bill Moyers' show last night reminded me how the an "Iraq team" in the White House created a false impression in the minds of the American public that Saddam Hussein and his Iraqi government were developing weapons of mass destruction, including nuclear weapons, and were closely linked with Al Qaeda; indeed, as a result of their campaign to convince the public many Americans believed that Iraq was implicated in 9/11, and that Iraq might supply Al Qaeda with nuclear weapons. If they did not know that much of the data that they were using in that campaign was erroneous, they should have.

I worked on two initiatives in the White House in 1976, one on international health and one on world hunger (which is itself illustrative of the difference between the Carter and the "W" Bush administrations). I also was a member of the interdepartmental team supporting a White House team that created an international science and technology initiative in 1976. Those teams were made up of people who understood the data that they were using very well, and worked very hard to create a fair and accurate presentation of that data. The key working teams were experts in the fields involved, reporting up the line to political appointees (who in turn reported to the president), We knew that the initiatives would have to be sold to the Congress and the public, but there was never any effort to shade the findings. I was involved in writing up the speech announcing one of those initiatives, and in developing a speech for President Carter on the other.

So in 30 years how did the White House staff go from trying to tell the truth to the public and the legislature to whatever it was that the Bush administration did?