Sean Penn sat on a wall?

“All the King’s Men”Columbia PicturesDirected by Steven ZaillianScreenplay by Steven Zaillian, based on the novel by Robert Penn Warren

Starring: Sean Penn, Jude Law, James Gandolfini, Kate Winslet, Patricia Clarkson, Mark Ruffalo, Jackie Earle Haley and Anthony Hopkins

Rated PG-13/120 minutesOpens Sept. 22, 2006Two-and-a-half out of four stars

Somewhere buried in the screenplay of “All the King’s Men,” there are two Willie Starks.

The first is a self-proclaimed “man of the people,” a man who pulled himself up from nothing and won the hearts of the people of Louisiana by fighting corruption, poverty and cutthroat capitalism. Then there is the second Willie Stark, the one who has embraced corruption as a necessary ally, the one who uses bribery and intimidation to get what he wants-a man browbeaten by the very system he sought to expose.

That is the soul of this story, and it could make for a great tragedy. Unfortunately, that soul remains six feet under in the finished version of “All the King’s Men,” based on the Pulitzer Prize-winning novel by Robert Penn Warren and the 1949 film that won Best Picture.

The two versions of Willie Stark in this film-the before and the after-are virtually indistinguishable. The tragic storyline is still in place. Willie (Sean Penn), a good old boy from a small hick town, rises up out of obscurity to become governor of the great state of Louisiana; but, as they say, power corrupts, and he soon becomes part of the problem-to the extent that the state Senate threatens to bring charges against him.

Of course, Willie’s fall from grace is helped along by the corrupt people with whom he surrounds himself, namely Lt. Gov. “Tiny” Duffy (James Gandolfini) — which, once again, reinforces the trend that every big fat guy in a movie has to be nicknamed “Tiny.” This, you see, is very clever irony.

Presumably, as the story unfolds, we are meant to see a change in Willie as his values deteriorate and the system gets the best of him. But Sean Penn doesn’t capture that — though inconsistent writing and possibly shoddy editing may contribute to this as well. Penn’s “dual” performances are identical. He’s maniacally bombastic and unlikable before, and he’s maniacally bombastic and unlikable after. During the “big speech” scenes, Penn follows every scenery-chewing impulse in his body. If only Willie Stark had a mustache, he could twirl it with the best of them.

Such a glaring weakness dilutes the power of this moral fable. And Willie’s characterization is only the first of the film’s problems. Zaillian — typically known as a screenwriter for such films as “Schindler’s List,” “Gangs of New York” and “Awakenings,” but also the director of “A Civil Action” and “Searching for Bobby Fischer” — takes a confusing approach to his story. Relationships are unclear, political motives are muddy and unresolved and, for a while, it’s hard to tell whether the film is linear or non-linear. And, like Penn, he submits to his most-overly melodramatic impulses, inundating us with extreme close-ups and run-of-the-mill “uplifting Oscar movie” music.

Curiously, the film seems to pick up steam when Willie Stark is treated as more of a peripheral character — or rather, a symbol — than the main character. Willie’s personal assistant is Jack Burden (Jude Law), an idealist, hopeless romantic and former journalist for The Chronicle (not this one), who gradually loses faith in the man and the message that he once championed. His complex relationship with an old flame, Anne Stanton (Kate Winslet), is captured with great sadness and simplicity, and makes for some of the film’s most effective scenes. Anne and her brother Adam (Mark Ruffalo, completely wasted in a tiny role) play into the larger picture, which reveals itself in the third act.

And in probably the best performance of the movie, Anthony Hopkins is Irwin, a retired judge who, nonetheless, still holds political clout and proves to be quite a bee in Willie’s bonnet.

All this combines for some quietly effective intrigue — but only in parts. “All the King’s Men” is so uneven that even the best parts never seem as effective as they should be. Because of the cast and crew involved, this was once considered an Oscar shoo-in. Instead, it seems like a wasted opportunity.

“Yes, Tiny, I want a Model-T filled with fried cat parts. Is that too much to ask?” James Gandolfini takes notes for Sean Penn in “All the King’s Men.”