So Partridge isn't exactly suited to be a leader. Sure, he was supposed to be the "leader from within" ever since Sedge was turned over to Special Forces, but that doesn't mean he's a great leader.
For starters, Partridge is stuck on the mindset that he has to be 100% good:
Partridge wants to be good. He's always wanted to be good, hasn't he? Right now, he has to decide how they're all going to try to survive. (64.186)
But as we know, you can't always be Mr. Nice Guy. Though telling the truth about the Detonations was the honest thing to do, it wasn't the right thing to do. Partridge is impulsive, and he doesn't think of the consequences of his actions—Pures can't handle the truth, and they start committing suicide by the dozens.
Even when Partridge is faced with the very real evidence of suicide, Partridge stands fast. Check it out: a Pure is about to for-real jump in front of a for-real train. And what does Partridge do? He continues to stand by the truth:
"What I said is the truth. And I'm not taking it back. In fact, I'm going to lead us into the future with that truth." (6.24)
Then the man promptly jumps in front of the train. Splat. Train: 1. Partridge's diplomacy: 0.
Partridge needs to learn a little something about his own people. The Pures inside of the Dome are very fragile. Sure, the truth is a way to wake them up from the lie they've been living, but it's also a way of completely destroying them internally. Partridge might be trying to be an altruistic leader, but he really just turns out to be a reckless leader who gets his people killed.
We can even see how he isn't fit to be president right from the beginning. When Weed tries to step all over him, he shouts:
"I'm not a figurehead to be propped up for weddings and memorial services, Weed. I'm in charge, okay? I'm in charge of everything!" (18.51)
Yeah, this sounds like an elementary school kid who was just put in charge of leading the class in arts and crafts: I'm in charge of everything! Do what I say! More glitter on that hand-turkey! The power gets to Partridge's head… and because of that, Partridge actually becomes powerless.
Yep: even though he's technically the president of the Dome, Partridge has no power. In fact, his father is still the one with power—even though he's dead:
His father's still calling the shots from the grave. "I don't know if there's anything I can do." (6.218)
Really, Part? You're just going to give up because a dead guy was smarter than you? Partridge's father has been manipulating him since Pure: Ellery wanted Partridge to find Pressia, he wanted Partridge to become the leader of the Dome, and he probably wanted him to be a patricidal murderer too.
But just because he's been manipulated every step he takes, that doesn't mean he should give up so easily, right? Yet, Partridge has a weird tendency to want to throw in the towel. He gets discouraged pretty easily for someone who is supposed to be in power.
In fact, this combination of power and his total lack of spine ends up destroying him:
He hates himself. He hates both worlds—inside the Dome and out. (64.193)
Partridge is utterly exhausted, and every move he makes seems to fail. He really does say it best when he's at his wedding:
I'm an impersonator impersonating myself. (41.34)
Partridge might think he's acting at certain times — dancing with Iralene, picking out wedding clothes, saying the marriage vows — but he's really just himself the whole time. He's his father's sheep: that's what he's always been, and that's what he'll always be.
But hey, at least he has a witty sense of humor:
"Act natural?" Partridge says. "Isn't that an oxymoron? I'm acting and so it's not natural." (34.3)
If we really want to burn Partridge down to a crisp and analyze his very ashes, he's really just Willux's son. He's just a pawn in Ellery's chess-game. He's Ellery's personal voodoo doll.
For the first two books, we really want to believe in Partridge. He shows signs of strength and resiliency, and he pretty much looks like he might be the savior after all. But his true colors come out in Burn.
"He's in me. He's inside of me. My father. He's not just in the air all around us. He's inside of my body. His blood is my blood." (64.119)
That's right, Partridge is a murderer just like his father. He's not an evil murderer — but he's still a murderer.
The only redeeming quality we get out of Partridge in Burn comes at the very end. Instead of running from the Dome, he decides to stay. He even says:
"This is a ship. I think if it goes down, I should go with it." (64.210)
Now that's the Partridge that we all know and love. He stays true to his promise to Iralene, and he decides to finally own up to his mistakes.
Partridge is a pretty tragic character: he wants to be good, and all he wants is to make people happy. But he can't, simply because he's Ellery Willux's son. He was born the son of an evil genius—that's his tragic flaw.