The Simpsons drive to the park for a picnic but discover that it has been overrun by mosquitoes. While heading home, the family finds an Indian casino. Homer and Bart go inside, leaving Marge (who is still recovering from her gambling addiction from "$pringfield") and Lisa (who is on the fence about her stance on the morals and ethics of Indian gambling) in the car.
Bart is turned away because of his age but is able to sneak in by hiding in ventriloquist Arthur Crandall's dummy case. During Crandall's performance at the casino, Bart bursts out of the case and gets caught by casino guards. He is sent to the casino manager's office, where the Native American manager shows him a vision of how his future will turn out if he does not change his ways.
Thirty years into the future, Bart is a 40-year-old beer-drinking slacker trying to launch his music career after dropping out of the DeVry Institute. The only gig Bart can get is at a beach bar owned by Nelson Muntz, and even then, Bart is only paid in popcorn shrimp. He survives by mooching off his parents and their neighbor Ned Flanders. Bart lives with Ralph Wiggum in a beach cottage by the shore, from which Bart finds out that he has been evicted after his disastrous concert at Nelson's bar. Meanwhile, 38-year-old Lisa is the first straight female President of the United States, trying to rebuild the country after the economic downfall during the rule of Donald Trump.
Bart disrupts one of Lisa's addresses to the nation to promote his music career, which leads Lisa to be branded unpopular when Bart sings to the public on live television that Lisa will be imposing a tax to get the country out of debt.
Lisa later meets with the leaders of America's creditor nations, who demand that America pay them back. Bart steps in and uses his skills at stalling debt collectors to save the day, pleasing Lisa who had previously been mad at her brother. As a thank-you, Bart asks Lisa to "legalize it", and Lisa says she will.
Meanwhile, Homer has heard about gold buried by Abraham Lincoln on the grounds of the White House and searches for it. When he finally locates the "gold", it is in fact a chest with a scroll in it that Lincoln had written on explaining that his "gold" is "in the heart of every freedom-loving American." Homer does not appreciate the metaphor and angrily curses Lincoln.
After the vision is over, Bart promises that he will change. Lisa finds Bart and tells him that the family has been kicked out of the casino after Homer pushed a waitress and Marge lost US$20,000. Bart tells Lisa about his vision of the future where he has a rock band and a moped, while downplaying Lisa's future presidency as "some government job."