Now, I transcribed this all myself, so be appreciative.
Malcolm: You know what? I'm glad this happened! Now my life looks exactly like I feel! [A beat--at Lois] How could you screw me over like that?
Lois: Because you were gonna take that job, and we are not going to let you throw your life away.
Malcolm: How is being rich throwing my life away?
Lois: Because, it's not the life you're supposed to have! [a beat, Hal takes her side] The life you're supposed to have is you go to Harvard. You earn every fellowship and internship that have. You graduate first in your class, and you start working in public service. Either as a district attorney or running some foundation. And then you become governer or a mid-size state. Then you become president.
Malcolm: [shocked] What?
Lois: Of the United States.
What does Hal say in "Baby part 1"? "'Something will come up' is code for Malcolm will fix it." He's right. This part of the scene, if taken 100% face value isn't so much Lois saying what he will do because she demands it. She's saying what he will do... because she knows him.
Hal taking her side is a brilliant piece of direction. This isn't Lois ranting. This is Lois pouring her heart out, and he believes completely that this is the correct path for Malcolm.
The rich angle is important, too. All through the series, Malcolm has been bemoaning his families lack of money (well, so have the rest), but it's been more obvious through Malcolm's eyes due to his Krelboyne friends all seemingly very well off. The job wasn't what Malcolm was interested. It was the money. And that's not good enough to settle your whole life over.
Malcolm: Dad!
Hal: I'm sorry son, it's true.
Francis: Thought you knew.
Hal: Out expectations started out much smaller, but you just kept upping the ante.
With this part of the scene, it's very important to watch the family as they move. Especially Francis and Piama. The two people in the show that are first to call Lois out on her overbearing attitude. They agree one hundred percent. Everyone in the scene is agreeing, they all see it as the truth, and they're all seperated from Malcolm, as well, which is a more subtle touch. His in ability to see the truth, and to view the bigger picture, is what keeps him alone, something that Lois, again not completely references later in the scene.
Malcolm: What if I don't want to be president?
Lois: It's too late for that. You're gonna do it.
Malcolm: [Flinging sludge from his pants] Oh really? Have you decided my position on capital gains tax cuts? What are my foreign policy objectives?
Lois: It doesn't matter. What matters is that you will be the only person in that position who will ever give a crap about people like us. People like us have been getting the short end of the stick for thousands of years, and I for one? Am sick of it. Now you are gonna be president mister and that's the end of it.
This is mostly Lois and Malcolm butting heads because that is what they do. Remember Mono?
Again, the wording can seem selfish. "And I for one? Am sick of it", especially, but it's not just the words. It's her movement, she's talking about her specifically, but she moves her arm in a wide gesture. The whole family is whats important, and until Malcolm becomes president, the underdog doesn't win. That's what she's truly sick of.
Malcolm: Did if it ever occur to you, I could have taken this job, gotten really rich and bought my way into being president?
Lois: Of course it did. We decided against it.
Malcolm: [Angry] WHAT?
Malcolm's anger explodes. Blah blah blah. It's clear at this point, that entire family knows about this. Lois is referring to 'we' not 'I'. She's a very 'I' statement person.
Lois: Because then you wouldn't be a good president. You wouldn't have suffered enough.
Malcolm: I've been suffering all my life!
Lois: I'm sorry it's not enough. You know what it's like to be poor and you know what it's like to work hard. Now you're gonna learn it's like to sweep floors and bust you're arse and accomplish twice as much as all the kids around you. [A beat] And it won't mean anything. Because they will still look down on you. And you will want so much for them to like you, and they just won't. And it'll break your heart. And it'll make your bigger and open your eyes and finally you will realise there is more to life than proving you're the smartest person in the world. I'm sorry Malcolm, you don't get he easy path, you don't get to just have fun and be rich and live the life of luxury.
Hal: That's Dewey.
Dewey: Really? [Hal nods]
As mentioned above, this about the underdog. This is about the poor people who strive to get places and just don't. Because everyone looks down on them. In a more personal way, this really strikes a cord with Malcolm, because the bane of his existence for the series has been about his intelligence. And him proving it, not always for the sake of proving it, but often. Because of this and his desire to be liked, and now matter how hard he tries they just don't, he could never see the big picture.
They do, and they're telling him before he can screw it up. Because if he's going to be president, if he's going to be as good as he can be? He needs to remember where he came from. There's no way around it. Then he can actually change things for the better.
(And being poor, and busting my arse, and wanting people to like me, and figuring out there's more to life than showing people how smart I am? Yeah, I agree 100%)
Malcolm: This is unbelievable. You actually expect me to be president. [A beat] No no, I'm sorry you expect me to be one of the greatest presidents in the history of the United States.
Lois: You look me in the eye, and you tell me you can't do it.
His silence says everything. He knows she's right. The whole family knows it, Malcolm his slight movement gives it away on two levels. He desperately wants to say something, but he can't ("I want to run, but my legs won't move"), and he's trying to hold his ground, as his body moves ever so slightly
towards his family.