I think what you're saying is correct -- mostly. Just taking a cross section of threads at FR you would find that even a group of fairly homogeneous political proponents do indeed question each other pretty closely on issues both great and small. Being social animals requires both cooperative and competitive behavior.
But... Some of this mechanism has clearly broken down. For example, it isn't merely a few well known physicists who object to AGW. I believe I saw one survey where as many as 45% of physicists were either skeptical or believed the evidence for AGW was incomplete or wrong. That didn't stop the APS from adopting support for AGW as an "official" position. There now a great many scientists who apparently don't understand that taking a position in support of a political issue as scientists is not only against the canon of ethics, but it is extremely dangerous as well.
The position of the APS is a political position, not a scientific one. And that is the fault of "science" in the sense that it is a political position taken by scientists, speaking, not as liberal politicians but as scientists.
Over 31,000 scientists have expressed their disagreement with the AGW theories, people who are well educated in physics, meteorology, climatology, geology, chemistry, etc.
It is a matter of being heard. It is politically expedient to bury dissent on an issue which promises unprecedented political control for the Government, and a vehicle to wealth for those who embrace that control as well--all funded with the taxes of those who are subject to the most onerous provisions thereof.
Ultimately, the device is being used to destroy the economic engine which drives this nation and its ability to preserve its own liberty and project force elsewhere to maintain significance in the global arena.
This is no accident, and the falsification of scientific data by omission and/or commission is just a small part of a concerted effort which is being carried out in a broad spectrum of issues, from the invasion by illegal aliens, to environmental regulations which impede development of viable resources, to the current attempt to strip Americans of wealth by forcing them to buy insurance.
To anyone who takes a good look, it is apparent that, the greatest impediment to finding the truth in any matter is the perception foisted upon the public by the media, but that too works in concert with the rest to disable American industry (large and small) and to keep people from fighting the decline of this Repbulic.