Why not re-write the book as well, get rid of all that power and ethics stuff and make it into a straight action-adventure piece a'la "Tom Clancy's Op Center" or "The Poseidon Adventure"?
Okay, I'm being sarcastic.
By way of full disclosure, I haven't seen the new film yet, I will of course at some point (out of reverence and concern for Robert Penn Warren's original novel) but Sean Penn, Jude Law, Kate Winslet & Anthony Hopkins will have to go a ways to erase memories of the 1949 original.
I mean the cast is headlined by a Yankee and THREE Brits to cover the life and times of a southern demagogue, as my old co-worker the grouch would exclaim "What rubbish!"
I can see doing Huey Long as a fictional character, the late Kingfish lent himself to dramatic caricature but since "All the Kings Men" was done right the first time, why hash it out all over again?
John Dos Passos' "Number One" whuch is also a scherzo on the Life of Long has yet to be adapted, for that fact, Sinclair Lewis' "It Can't Happen Here" deals in a Huey Long's seizure of power in Washington DC....both are waiting in the wings for some enterprising producer to option.
Give some other scribblers a chance for Hollywood immortaility whydoncha?