In THE ATLANTIC, Mickey Edwards has a good time observing how both the GOP and the Democrats are dead certain they will win on health care in the U.S. Senate. Edwards notes, "both sides march forward with the confidence only certitude can bring."
Of course, certitude is nothing but savvy posturing. Trial lawyers use it all the time. "The jury was/are/had been with us." I have heard that so many times, at least from the trial lawyers involved in a particular trial. Speak to trial lawyers not involved in that particular trial and they will testify that there is no way to "read" a jury. There are ways to convince oneself that the jury is tending to think X or Y way. But over and over again juries have proved their readers wrong.
However, that tactic will be part of the high stakes melodrama of legislation and litigation for ever. The only pitfall in leveraging it is when the audience is intelligent and experienced. That audience will assume the creature who is so deeply certain is out of touch, insane, and just stupid.
Me? I don't use it, at least not in selling or actually working with the client on a project. Hard times have made them very smart.