*Although the rest of the cast -- especially the ever-excellent Sam Rockwell -- isn't far behind.
Strangely, I would only recommend Assassination to a select group; it was box-office poison, and for once, it's easy to see why: It's slow and long (160+ minutes), and if you don't buy the pace, you're gonna hate it. But if you're of the right mindset, there's just something hypnotizing about this story of early hero worship and celebrity (which, incidentally, is not unlike writer-director Andrew Dominik's only other, aforementioned, film, Chopper), as the aging outlaw James drifts through the downside of his train-robbing career -- with the ambitious, voice-cracking young Ford tagging along and, ultimately, doing away with his idol.
Getting euphemistic, I'll say the plot unfolds "methodically" and also episodically, but I'm not sure anything could/should have changed. Every frame seems perfectly placed, and not just aesthetically*. The dialogue, too, seems spot-on, allowing the story to advance without any sense of contrivance.
*The Film Official Challenge: How many words can I use that end in "ically"? Technically, I say four. At least in these two grafs.
The result: When Ford finally shoots James, you know absolutely why (at least in the context of the film), but without being beaten over the head with reasons. Also, you know the heroism eventually given Ford is not one found in fairy tales -- not one that will end happily, but not like the stuff of phony tragedy, either.
If the story sounds literary, that's because it is. The opening scene -- and various parts throughout -- are narrated as if being read from a book (perhaps this book). That narration is a useful tool, filling in blanks that often go untold in poor adaptations of subtext-heavy novels. In the end, everything is understood, everything is felt, everything is ... beautiful, even if tragically* so.
P_T_D once went to film school, but left because he found the job landscape too bleak. Now he is comfortably employed in the rock of stability known as journalism, and surely shall remain so until the end of time.