One way in which Shakespeare appeals to the aristocrats and the commoners in A Midsummer Night's Dream, is the Bard's inclusion of the supernatural—something people of all economic levels during his time believed in completely.

During the time of Shakespeare, the belief of fairies is persistent and widespread. Although Shakespeare may not believe in these mythological creatures himself, he does believe in using them for dramatic purposes.

A belief in the supernatural (anything that goes beyond what is seen as "natural") is not reflected only in what happens to the common folk, but also in what occurs with those of a more elevated class. While the Bottom (the weaver) and the other "players" are taunted and even (in Bottom's case) placed under a spell, the same thing happens to the young lovers, who are also the subject of Oberon's "love juice" as he tries to fix the difficulties between Helena and Demetrius, with comic results.

Shakespeare draws a line between the aristocrats and commoners, except when the supernatural steps in:

[Shakespeare] is also careful to make apparent the distinction between the court and the craftspeople, except, of course, when Bottom is beloved by Titania.

Titania is a member of the aristocracy of the fairy kingdom. Once again, it is only through magic that she and Bottom are involved in a romantic tryst. Her shock at the time they spend together is found in her response when the antidote is administered by Oberon, and she believes she had been "enamour'd of an ass" (IV.i.76), for only a spell of a supernatural nature could bring these two together:

TITANIA:

How came these things to pass?

O, how mine eyes do loathe his visage now! (78-79)

A common belief in the supernatural allows the different social classes to interact. And this interaction requires no "willing suspension of disbelief," for during the Elizabethan age, people of all socioeconomic classes believed in the power of the supernatural, as seen also in many of Shakespeare's other plays, including Julius Caesar, Macbeth and Hamlet, to name a few. The presence of ghosts, witches and fairies were elements of drama that allowed for the impossible to take place: for information to be shared between this world and "the next," for illusions to appear before the eyes of otherwise mentally sound characters, and for fear—and humor—to heighten the dramatic experience of theater-goers as they viewed the Elizabethan and Jacobean drama.

Additional Sources:

http://www.enotes.com/midsummer-nights-dream/demetrius-character-analysis

http://en.wikipedia.org/wiki/Suspension_of_disbelief