toughen up the skin of the bubble, further isolate themselves from any threatening pinpricks from the reality-based world, and double (quadruple/octuple) down on their commitment to craziness.
Some--a goodly number--of those who were never solidly into it will flake off, but there will remain a shrunken hard core of True Believers.
The best model for this comes from an old book, When Prophecy Fails, by social psychologist Leon Festinger, who infiltrated and recorded the unfolding history of a flying saucer cult, documenting what happened when the Space Brothers didn't show up to carry the cultists off to a better world.
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http://www.amazon.com/When-Prophecy-Fails-Leon-Festinger/dp/1891396986/ref=sr_1_1?ie=UTF8&qid=1352562295&sr=8-1&keywords=festinger+prophecy+fails
When Prophecy Fails [1956] is a classic text in social psychology authored by Leon Festinger, Henry Riecken, and Stanley Schachter. It chronicles the experience of a UFO cult that believed the end of the world was at hand. In effect, it is a social and psychological study of a modern group that predicted the destruction of the world, and the adjustments made when the prediction failed to materialize. "The authors have done something as laudable as it is unusual for social psychologists. They espied a fleeting social movement important to a line of research they were interested in and took after it. They recruited a team of observers, joined the movement, and watched it from within under great difficulties until its crisis came and went. Their report is of interest as much for the method as for the substance."-Everett C. Hughes, The American Journal of Sociology.