Take for an instance, the narrator in the tedious introductory sketch "The Custom-House" says:
It contributes greatly towards a man's moral and intellectual health to be brought into habits of companionship with individuals unlike himself, who care little for his pursuits, and whose sphere and abilities he must go out of himself to appreciate.
The age was more tolerant of rotundity in style, but "It contributes greatly towards" is not great style in any age, nor is the letter-to-the-editor cliche "a man's moral and intellectual health." The sentence wavers from the man to his unlikely companions, and back to him; it lacks direction.
Hawthorne also loves to swell his sentences with parenthetical clauses. When he explains why Hester Prynne does not leave Salem, the parenthetical clauses get in the way, instead of performing little hops of insight:
It may seem marvellous that, with the world before her--kept by no restrictive clause of her condemnation within the limits of the Puritan settlement, so remote and so obscure--free to return to her birthplace or any other European land, and there hide her character and identity under a new exterior, as completely as if emerging into another state of being--and having also the passes of the dark, inscrutable forest open to her, where the wildness of her nature might assimilate itself with a people whose customs and life were alien from the law that had condemned her--it may seem marvellous that this woman should still call that place her home, where, and where only, she must needs to be the type of shame.
The three parenthetical clauses (between the repetition of "It may seem marvellous") are syntactically equivalent but are not equal ideas. The first ("kept by no . . . Puritan settlement") is a condition of her liberty, the second and third ("free to return to her birthplace . . ." and "having also . . . the forest open to her") are that liberty's possible destinations. The syntax hides that relationship between the three places (Puritan settlement, Europe, and forest), instead of clarifying or amplifying it.
The narrator continues:
But there is a fatality, a feeling so irresistible and inevitable that it has the force of doom, which almost invariably compels human beings to linger around and haunt, ghost-like, the spot where some great and marked event has given the colour to their lifetime; and still more irresistibly, the darker the tinge that saddens it.
Fatality is "a feeling so irresistible and inevitable that it has the force of doom," and so the appositive phrase adds very little to the idea of fatality. Consider the difference if the two were switched: "But there is a feeling so irresistible and inevitable that it has the force of doom, a fatality . . . ." The single word "fatality" would then not only concentrate the idea before it, but also give it the force of a recognition. Also, the qualifier "almost" in the passage quite spoils the effect of inevitability; what to make of a fatality that is almost invariable? And what is "still more" irresistible than irresistible? or more like a ghost than to haunt?