I seem to recall that this was well known before the 70's. We were taught in school that even though a delegate was "bound" by the state that they could vote their conscience. (of course that is relying on a very old memory!!)
Exactly. If there is one shining diamond that's coming out of this piece of coal election, is that it's forcing people who are old enough to brush up on their Civics lessons and, for those not, to learn about how our political process works for the first time.
If they don't like what they are discovering they can work to change it.