[1] In the episode, what begins as an innocent game between the boys turns serious when Cartman joins the U.S. Border Patrol.
The episode was written by series co-creator Trey Parker and is rated TV-MA L in the United States.
The couple in the car, believing Butters to be a Mexican immigrant named "Mantequilla" (Spanish for "butter"), take him to their home and employ him as a stereotypical Mexican servant, giving him menial jobs to perform such as cleaning windows and washing dishes.
However, the couple eventually abandons Butters at an El Pollo Loco restaurant, believing that he needs to be with his "own kind" to be happy.
The staff recognize him from "missing" posters put up by his friends and, believing him to be someone famous, they start to question the value of their new lives in the United States.
With the Border Patrol's help, Butters successfully eludes Cartman and re-enters the United States, winning the game.
In response, Butters stands up and gestures with his hands, causing Mexicans everywhere to chant loudly enough for the boys to hear them.
Club graded the episode a B+, stating, "'The Last of the Meheecans' isn’t really about immigration reform so much as it's about the narcissistic viewpoint that America must be, as a point of irrefutable fact, the best place in the world to live.
For some, that’s a fairly ballsy thing to say, but the way in which Parker/Stone say it bypasses political grandstanding and casts their gaze instead on our supposed understanding of those that have immigrated to America and currently live/work here".