WHen did the term "Conservative" become synonymous with "out of touch with reality" in US English?

Amanda Marcotte wrote an article that answers this question and makes some good points about that change:

The thing is, shameless lying and ignorance works surprisingly well as a debate tactic. It’s hard to argue with someone who not only has signaled that he doesn’t care what the truth is but is downright proud of how little he actually knows. Such a person is not amenable to being educated. Once the pretense of really caring one way or another about what is right and what is wrong has been abandoned, all avenue of discourse is shut down.

It gets even better:

At the end of the day, the problem is one of identity. The conservative identity is one of being opposed to everything liberal, to the point of despising anything even associated with liberalism. As liberalism has increasingly been aligned with the values of empiricism and reason, the incentives for conservatives to reject empiricism and reason multiply. To be a “conservative” increasingly means taking a contemptuous view of reality. And so the proudly ignorant grow more belligerent, day after day.