When has a policy discussion been politicized?

The Belmont Club asks:

One of the questions I'm interested in exploring is whether politics somehow prevented environmentalists from reaching the conclusions described by the NYT years earlier; and if the answer is yes, whether there is any way, in principle, one can detect whether politics is twisting a current public policy debate away from its rational path.

I wanted to highlight this comment by "meme chose", which I though was wonderful:

The question you focus on, "whether there is any way, in principle, one can detect whether politics is twisting a current public policy debate away from its rational path", is an interesting one.

During the whole time that I have paid any attention to matters of politics and public policy (about 35 years, living primarily in Europe and the US) the answer has appeared to me to be clear and unchanging. The best indicator as to whether this twisting is going on is the readiness of otherwise reasonable people to join in campaigns of character assassination against anyone, particularly anyone with relevant professional expertise, bold enough to suggest that there might be two sides to the argument. I have found this characteristic an infallible tipoff that what is being defended is an article of faith rather than a rational proposition, pro or con....

My own first reaction on seeing this phenomenon is to think that there is probably something fishy about arguments or causes which need defending in this way, but I've been forced to conclude over time that the chance to sign up for a crusade is unfortunately at least as seductive and deeply satisfying to secular folk as it sometimes is to the religious.

That's an excellent standard: "the readiness of otherwise reasonable people to join in campaigns of character assassination against anyone... bold enough to suggest that there might be two sides to the argument."

(My somewhat more cynical answer would be: "Is there a policy discussion? Then it has been politicized.")