What makes this feel less like a Wallace story (and I'm not claiming to be knowledgeable about this fancy literary business) is the specificity of context. It's not that Wallace isn't a detailed writer, not at all. There are parts of his non-fiction where DFW's keen eye for efficient, yet insanely detailed description is nothing short of impressive. And there are parts of his fiction where the detail is so completely and exhaustively fleshed out that it becomes frustrating, which maybe is the function of it. For me, though, the vast detail develops such complete dimension to characters and situations that might be considered "absurdist" that they become very believable. This is maybe most apparent in the (in)famous Infinite Jest, but it's definitely also true of "Lyndon," when we consider the whole bodily function thing, and just the general aura of Lyndon. The opening line of the story, I mean come on.
All that being said about his detailed writing, I think Wallace usually leaves some things about his characters to be open, which is I guess harder when you're writing about a real person. Little about this story is open: it's mired somewhere between fact and fiction, and our only true in-road is the fictional Boyd, and he's the man we learn the least about (married, then not, and why?). As for Lyndon himself, he is often described through the lens of a caricature, and his big speeches are, I assume, meant to mirror or mock the man's actual policies.
This is completely unrelated but I found my favorite DFW story online, "Incarnations of Burned Children," which I think gives an idea of what I was talking about with character development. This story is only like two pages long but even so, if he wanted to be clearer about his characters he could have easily been. That's the kind of writing I'm used to reading from him, and it's not that "Lyndon" was disappointing in any way, but.. I don't know! I don't know.
Incarnations of Burned Children
by David Foster Wallace
(taken from Esquire)
The Daddy was around the side of the house hanging a door for the tenant when he heard the child's screams and the Mommy's voice gone high between them. He could move fast, and the back porch gave onto the kitchen, and before the screen door had banged shut behind him the Daddy had taken the scene in whole, the overturned pot on the floortile before the stove and the burner's blue jet and the floor's pool of water still steaming as its many arms extended, the toddler in his baggy diaper standing rigid with steam coming off his hair and his chest and shoulders scarlet and his eyes rolled up and mouth open very wide and seeming somehow separate from the sounds that issued, the Mommy down on one knee with the dishrag dabbing pointlessly at him and matching the screams with cries of her own, hysterical so she was almost frozen. Her one knee and the bare little soft feet were still in the steaming pool, and the Daddy's first act was to take the child under the arms and lift him away from it and take him to the sink, where he threw out plates and struck the tap to let cold wellwater run over the boy's feet while with his cupped hand he gathered and poured or flung more cold water over his head and shoulders and chest, wanting first to see the steam stop coming off him, the Mommy over his shoulder invoking God until he sent her for towels and gauze if they had it, the Daddy moving quickly and well and his man's mind empty of everything but purpose, not yet aware of how smoothly he moved or that he'd ceased to hear the high screams because to hear them would freeze him and make impossible what had to be done to help his child, whose screams were regular as breath and went on so long they'd become already a thing in the kitchen, something else to move quickly around. The tenant side's door outside hung half off its top hinge and moved slightly in the wind, and a bird in the oak across the driveway appeared to observe the door with a cocked head as the cries still came from inside. The worst scalds seemed to be the right arm and shoulder, the chest and stomach's red was fading to pink under the cold water and his feet's soft soles weren't blistered that the Daddy could see, but the toddler still made little fists and screamed except now merely on reflex from fear the Daddy would know he thought possible later, small face distended and thready veins standing out at the temples and the Daddy kept saying he was here he was here, adrenaline ebbing and an anger at the Mommy for allowing this thing to happen just starting to gather in wisps at his mind's extreme rear still hours from expression. When the Mommy returned he wasn't sure whether to wrap the child in a towel or not but he wet the towel down and did, swaddled him tight and lifted his baby out of the sink and set him on the kitchen table's edge to soothe him while the Mommy tried to check the feet's soles with one hand waving around in the area of her mouth and uttering objectless words while the Daddy bent in and was face to face with the child on the table's checkered edge repeating the fact that he was here and trying to calm the toddler's cries but still the child breathlessly screamed, a high pure shining sound that could stop his heart and his bitty lips and gums now tinged with the light blue of a low flame the Daddy thought, screaming as if almost still under the tilted pot in pain. A minute, two like this that seemed much longer, with the Mommy at the Daddy's side talking sing-song at the child's face and the lark on the limb with its head to the side and the hinge going white in a line from the weight of the canted door until the first wisp of steam came lazy from under the wrapped towel's hem and the parents' eyes met and widened--the diaper, which when they opened the towel and leaned their little boy back on the checkered cloth and unfastened the softened tabs and tried to remove it resisted slightly with new high cries and was hot, their baby's diaper burned their hand and they saw where the real water'd fallen and pooled and been burning their baby all this time while he screamed for them to help him and they hadn't, hadn't thought and when they got it off and saw the state of what was there the Mommy said their God's first name and grabbed the table to keep her feet while the father turned away and threw a haymaker at the air of the kitchen and cursed both himself and the world for not the last time while his child might now have been sleeping if not for the rate of his breathing and the tiny stricken motions of his hands in the air above where he lay, hands the size of a grown man's thumb that had clutched the Daddy's thumb in the crib while he'd watched the Daddy's mouth move in song, his head cocked and seeming to see way past him into something his eyes made the Daddy lonesome for in a strange vague way. If you've never wept and want to, have a child. Break your heart inside and something will a child is the twangy song the Daddy hears again as if the lady was almost there with him looking down at what they've done, though hours later what the Daddy won't most forgive is how badly he wanted a cigarette right then as they diapered the child as best they could in gauze and two crossed handtowels and the Daddy lifted him like a newborn with his skull in one palm and ran him out to the hot truck and burned custom rubber all the way to town and the clinic's ER with the tenant's door hanging open like that all day until the hinge gave but by then it was too late, when it wouldn't stop and they couldn't make it the child had learned to leave himself and watch the whole rest unfold from a point overhead, and whatever was lost never thenceforth mattered, and the child's body expanded and walked about and drew pay and lived its life untenanted, a thing among things, its self's soul so much vapor aloft, falling as rain and then rising, the sun up and down like a yoyo.
