Marge's campaign slogan "I'm with Hair" is a reference to Hillary Clinton's 2016 presidential campaign slogan "I'm with Her".
As Marge and Homer walk through the "Marge Simpson Mayoral Library", a sign on the wall refers to the "Molasses Disaster of '22". There actually was a molasses flood in Boston, Massachusetts, on January 15, 1919, which killed 21 people and injured 150.
The first time someone other than "Diamond" Joe Quimby has been mayor of Springfield since Sideshow Bob defeated him for reelection in Sideshow Bob Roberts (1994), though a council of "learned citizens" also ran Springfield during his absence in They Saved Lisa's Brain (1999).
The episode title is a reference to the lyric "The old gray mare, she ain't what she used to be" in the folk song "The Old Gray Mare", which was performed previously in Krusty Gets Kancelled (1993).