Shelly Levene bears the marks of a classic American theatre archetype: the beleaguered salesman. He's a descendant of Willy Loman and The Iceman Cometh's Hickey—guys that live and die with the sale, who were at one point in their lives the best in the biz.
Like his predecessors though, time has caught up with Levene. He's in his fifties, and sales is a young(er) man's game. While he struggles, the younger Roma sits atop the leader board.
Levene might be down on his luck and a man in decline, but before we bust out a tiny violin, let's also make note of his complexities. Despite his professional shortcomings he is—in his own way—just as arrogant as Roma. Consider this: Levene is belligerent toward Williamson in the same way that Roma is. In addition to this, he also comes off at times as kind of a whiny, desperate guy, behaving in ways that don't exactly elicit sympathy from readers/the audience or those around him.
It isn't all bad though, when it comes to Levene. Mamet instills in him a code of honor. This code is never entirely clear, but we understand that Levene has a very strict idea of how business and life should be conducted; we also understand that these younger folks don't operate with the same code, that they just don't understand how it used to be. Here's a snippet from his Act 1, Scene 1 conversation with Williamson:
LEVENE: I'm older than you. A man acquires a reputation. On the street. What he does when he's up, what he does otherwise… (1.1.217-220)
In other words, Levene knows how to act when you're on top of the board and when you're struggling—that's how he built his reputation, which is something he places a lot of stock in. It is important to note that out of all of the characters in the play, Levene is the only one that seems fixated on how a man should and shouldn't act and, in this way, through Levene we see a sort of salesman's code of honor. The presence of this code isn't automatically a good thing though, as it is also a sign that Levene sees himself as a man of a different era, and in this way his personal code doesn't just guide him—it also keeps him separate.
And, of course, a personal code only gets you so far when you still need others to validate you. Levene believes he behaves the way a man should, and yet he needs Williamson to agree—the code doesn't help Levene stand on his own. He clings to his ideas of manhood and fixates on his past accomplishments, ultimately leading him to make the decision to rob the office, which pretty much marks his end.
From the get-go, an audience can get behind Levene. Most of us understand desperation, after all, and most of us can appreciate a man who still tries to conduct himself with honor and class anyway. It is possible this is all a big show on Levene's part, and it is debatable as to whether or not he's any better than any of his coworkers—no matter your assessment, though, through Levene Mamet gives us something to hold on to, a character we can glimpse ourselves in.
Just in case we can't sympathize with our aging hero though, Mamet gives him a little extra to humanize him:
LEVENE: I'm asking you. As a favor to me? (Pause.) John. (Long Pause.) John: my daughter… (1.1.259-260)
Uh-oh—Levene has a daughter. Not only that, but it seems like something is wrong with her, right? After all, every time he's truly desperate, he brings her up—she must need Levene for support or something. You'd have to have a pretty hard heart not to sympathize with this. Poor Levene is just trying to do what he needs to do to take care of his family—specifically his daughter—who needs help for some reason, right? Right?
Not so fast. While the audience can jump on board with Levene right away because he has to help his daughter, in actuality we know nothing about her. We're in a world of salesmen who turn out to be talkers and liars for a living, and Mamet never gives us any information about Levene's daughter at all. For all we know, this is some Catfish hoax before catfishing ever existed. We ultimately never know if we can take Levene at his word, and the idea that no one (including Levene) can fully be trusted plays right into the mystery of the play. We really can't know who robbed the office, because any of these men seem fully capable of it.
There's no proof either way about Levene's daughter; she may very well be sick. For Mamet's sake though, she is real, and like other women mentioned in the play, she simply serves to shake the men:
This community of men acknowledges the identity of Harriet Nyborg, recoils from the determined voice of Jinny Lingk, and momentarily goes mute at the mention of a female child. Something revelatory is gained. (Source)
So what exactly is gained from this? Well, to these men, women don't even belong in the conversation. If they are something pure (like a child), then they shouldn't be dragged through the muck of this world; and if they are something powerful (like Lingk's wife), they must be ignored, because a man should not have to answer to anyone.
Gender arguments and imaginary people aside, the mention of Levene's daughter serves to humanize him. We as an audience relate to his struggle from the beginning, and we root for him. Williamson is demonized as a corporate cog just filling his purpose in the machine, while Levene is just an ordinary guy trying to get by for himself and the people he loves.
Levene starts the play, then disappears for quite a while, and when he finally returns in Act 2, he's a new man. He's energized and ready to take on the world. He's made a sale for upwards of $80,000, and he's ready to reclaim his place on the board; he bonds with the younger Roma, and takes on a somewhat avuncular role. This is the guy we rooted for, and he's done what he desperately needed to do. Yay.
Victory is short-lived for Levene though. His big sale ends up being a no-go, plus it turns out that Levene is the thief who broke into the office and stole the leads. Desperation led him to do it, and we might not even hold his actions against him, but Mamet doesn't create a world in which Shelly Levene can succeed. His time has passed him by.
Levene may have been willing to do whatever he deemed necessary to survive, but ultimately he's as responsible for his downfall as he is for his brief burst of success. See, Levene has a sort of tragic flaw: he just can't keep his mouth shut, especially when it comes to an opportunity to rail on Williamson. We saw this in the first scene between the two, when Levene chastises Williamson while also asking for his help, and it rears its ugly head again in the rant that brings Levene down:
LEVENE: You're scum, you're f***ing white-bread. You be as cold as you want. A child would know it, he's right. (Pause.)(2.1.1015-1018)
If Levene could have just let sleeping dogs lie and refrain from having to prove his superiority over Williamson, he might have gotten away with his crime. But Levene is no saint—he's flawed just like the rest of them, and the world he lives in has passed him by.
No matter how respectable his personal code or how dependent upon him his daughter may be, things do not end well for the aging salesman Shelly Levene.