The final play in Richard Nelson’s trilogy “The Gabriels: Election Year in the Life of One Family,” now at the Public Theater, is set in the kitchen of the Gabriel family home in Rhinebeck, New York a couple of hours before the polls close on Election Day. The characters are the same as in the first two plays: Mary Gabriel (the superb Maryann Plunkett), a retired doctor, was the third wife and now widow of Thomas Gabriel, a playwright who died exactly a year ago. His younger brother George (Jay O. Sanders), a cabinetmaker, also taught piano until hard times forced them to sell the family piano. George’s wife Hannah (Lynn Hawley) works for a local caterer, but business is slow so she is also working part-time as a maid in a nearby hotel. Their son Paul is away at college, but his future there is uncertain because of their reduced financial status. George’s sister Joyce (Amy Warren), an unmarried assistant costume designer, is visiting from Brooklyn. Patricia (Roberta Maxwell), George and Joyce’s mother, who resides in a nearby assisted living facility, has had a stroke that left her partially paralyzed. Thomas’s first wife Karin (Meg Gibson), an actress and teacher, is renting the room over the garage. She is performing a solo piece that evening based on the writings of Hillary Rodham Clinton. The modest supper of shepherd’s pie and paintbrush cookies they are preparing may be the last time the family is together in the family home. A financial crisis brought on by Patricia’s gullibility has forced the sale of the house. Their conversation ranges far and wide, from vintage cookbooks to gentrification to outside money’s influence on local politics. In preparing the house for sale, they run across a box of letters sent to Patricia when she was 13, shortly after the sudden death of her older sister. The attempt to tie the reasons for the sister’s death to a notorious incident long ago at Harvard seemed clumsy and out of place. The Gabriels do not yet know the election results, but their future does not look bright regardless of the outcome. In contrast to the family in Chekhov’s The Cherry Orchard, their misfortune is entirely unearned. Anyone who has not seen at least the middle play of the trilogy may not get a lot out of this one. The ensemble cast is outstanding. Susan Hilferty designed the costumes and, with Jason Ardizzone West, the cozy set. The playwright directed. Running time: one hour 45 minutes; no intermission.