Now the idea of being united against an antipope is very Catholic indeed.
If this is true, then there would have been many times in the history of the Catholic Church when the laity would have been united against the Pope. Would you care to explain all of the those times in Church history?
And in order to be "united" all of the laity in the world would have to have been in on it. How would that have been possible in the old days, with limited communication?
Or are you perhaps speaking of the rebellions of Martin Luther, John Calvin, and the like? Though it wasn't specifically the Pope that they rallied people against, but rather they rallied against the Catholic Church in general, kind of like what you are doing.