The Heath Ledger posthumous Oscar campaign has kicked into full gear, with the late actor's Dark Knight co-stars rightly pronouncing the genius of Ledger's live-wire performance as the Joker and stumping for him for awards season. It's particularly touching that Aaron Eckhart, who plays the film's other bad guy, upstanding D.A. turned revenge-obsessed maniac Two-Face, is joining in the chorus, saying, "It wouldn't surprise me one bit" if Ledger is nominated. Why? Because if it wasn't for Heath Ledger, it would be Aaron Eckhart whose breakout performance and Oscar hopes we'd all be talking about right now.

The actor, who's long underwhelmed us, gives one of those where-the-hell-did-that-come-from? performances as Harvey Dent, going so far beyond anything we've seen him do in the past that it's as if he's on some kind of performance enhancer. He's vivid, specific, and energetic in a way we haven't seen before, and the performance is the first in his career that perfectly taps into Eckhart's weird mix of handsomeness and creepiness. As our friend the Slate critic Dana Stevens pointed out in the Dark Knight podcast we recorded earlier this week, his early collaboration with Neil LaBute, In the Company of Men, demonstrated the hint of corruption underneath Eckhart's matinee-idol face. It's the genius of The Dark Knight that Christopher Nolan not only explores that corruption, but makes it baldly literal, too — actually stripping away the skin from that square-jawed visage.

Two-Face's seared skull — not that different from the truly gross concept art leaked months ago — is a potent visual, but it's only part of a rich performance by Eckhart as a character who is truly the emotional core of The Dark Knight. In fact, his is the most complete performance in the movie, in the sense that Harvey Dent is the only character in the movie with anything like a full character arc. Heath Ledger might be more electrifying in every moment, but Aaron Eckhart has further to go; he doesn't have the benefit of appearing out of nowhere, with pockets full of "knives and lint." He has to start as a stolid, ambitious D.A. — a savior of Gotham — and turn gradually into a villain. That he sells that transformation so well, even before the accident that mutilates him, is a testament to the perfectly pitched performance Eckhart turns in. Heath Ledger will get the Oscar nomination, but when you're watching The Dark Knight at six o'clock Friday morning, don't forget to marvel at his forgotten co-star, too.