This study will examine whether addition of dexmedetomidine or clonidine (two alpha-2 adrenergic agonists) will improve the comfort of patients during spinal anesthesia for cesarean delivery. When added to standard spinal anesthesia consisting of bupivacaine (a local anesthetic) and fentanyl and morphine (two opioids), these medications may decrease some of the pulling/tugging/pressure sensations that patients sometimes feel during cesarean delivery, may prolong the anesthetic time, and may decrease postoperative pain.