Here is a silly piece on "Thought Control in Economics," thanks to Tyler Cowen at MR for the link. In teaching a economics principles course, we are not correspondents for Fox News, we are a science. We wouldn't expect medical schools to give a fair and balanced approach to the research from tobacco companies on why cigarettes don't cause cancer, but instead we would expect them to treat it like it doesn't exist.
Actually, I have always viewed the field of economics as being at the opposite end of this extreme. If it appears that there is too much conformity in the field, it is because what it good science gets incorporated into the mainstream within a few years.
Take for instance Austrian Economics, which from my understanding received a less than warmhearted welcome from the mainstream field for its more general principles. That did not stop the mainstream from adopting what is now arguably the most important concept in economics, marginal analysis.
Gary Becker was largely ignored for his work on the economics of crime and family initially, but ultimately it won him a Nobel Prize.
If memory serves me correctly (please correct me if you know I'm wrong), the AEA was originally a socialist organization, which is the historical reason they today maintains a progressive fee structure. I also think you would be much more likely to be able to publish something unlikely and outlandish than something everybody already accepts as true, especially in the highest journals like the AER.