Fantasies Can Be Beautiful, If Unreal

Yes, I am thinking of Avatar (2009). As well as Herbert Croly's The Promise of American Life (1911):

 Democracy must stand or fall on a platform of possible human perfectibility.

Of course, our Constitution's separation of powers and federalism is based on the belief that humans are not perfect or even close.  As Federalist 51 points out:

If men were angels, no government would be necessary. If angels were to govern men, neither external nor internal controls on government would be necessary. In framing a government which is to be administered by men over men, the great difficulty lies in this: you must first enable the government to control the governed; and in the next place oblige it to control itself. 

Can anyone think of a better statement of progressive vs. Constitutional thought?  Progressives intend to perfect human nature by banning disapproval of alternate sexual behaviors (not just LGBTIQABCDEFGEIEIO, but also B&D , S&M, and "child brides.")  The Soviet Union attempted to create New Soviet Man; people who lived there at the end could attest to how far short of this goal the people became.  Read Belenko's Mig Pilot.

As my wife would point the belief in perfectability is the lie Satan told Eve in the Garden:

4 “You will not certainly die,” the serpent said to the woman. 5 “For God knows that when you eat from it your eyes will be opened, and you will be like God, knowing good and evil.”

Of course, there are more modern versions of this:

19 And again, verily I say unto you, if a man marry a wife by my word, which is my law, and by the new and everlasting covenant, and it is sealed unto them by the Holy Spirit of promise, by him who is anointed, unto whom I have appointed this power and the keys of this priesthood;...

20 Then shall they be gods, because they have no end; therefore shall they be from everlasting to everlasting, because they continue; then shall they be above all, because all things are subject unto them. Then shall they be gods, because they have all power, and the angels are subject unto them. [Joseph Smith, Doctrines and Covenants, 132:19-20.] [emphasis added]

I used to wonder why polygamy so upset Christians against Mormons in the 1840s; this is far worse than polygamy: it is blasphemy that would have gotten you extra crispy in the 16th century; whipped and expelled from the colony in the 17th century.