Alicia Clare Vanderbilt's life is upended when she receives a pocket call from her husband Johnny Roy Smith, while he's having sex with a strange woman. The night after, Johnny returns to their home in Cold Spring. The couple's kids, Gina and Jeremy, 19-year-old twins, are in the house, so Alicia pretends to be slumbering; she screams internally as Johnny caresses her cheek and kisses her softly before leaving the bedroom. The following day, Alicia confronts Johnny about his infidelity. In the weeks to come, both Johnny and Alicia look back at their marriage and realize that twenty years with differing views on political issues have driven a wedge between them. Towards the ending of the novel, the 2024 presidential race serves as the backdrop for the narrative, and, as Johnny moves out of the house, and Gina decides to live with him, the question remains: will the family crumble entirely as they, and their country, move into a new era?

"Dissension" explores various minefields in US politics: abortion laws, gun laws, race, and immigration. Simultaneously, the novel attempts to explain why Donald Trump so relatively easily defeated Kamala Harris in the 2024 election.