Marco Rubio titled his autobiography American Son. The book, whose cover shows the 43-year-old senator without a tie, is meant to convey youth. But it actually explains why, when it comes to Cuba policy, Rubio’s views are so old.

In opposing President Obama’s decision to restore diplomatic relations with Havana, Rubio speaks not for his own generation of Cuban Americans, but for his parents and grandparents. According to a 2014 poll by Florida International University, Cuban Americans in Miami who are of Rubio’s age and younger overwhelmingly back restoring diplomatic relations with the island. Among those 45 to 64, the margin is 36 points. Among those aged 30 to 44, it’s 56 points. Among those younger than 30, it’s a whopping 76 points. Miami Cuban Americans over the age of 65, by contrast, oppose restoring diplomatic relations by 18 points. In Rubio, they have their champion.

For Rubio, filial piety has meant adopting the very Cold War outlook that most of his peers have shed. Students of generational identity, starting with Karl Mannheim, have long observed that people are disproportionately influenced by the events that occur in their late teens and twenties, once they leave their parents’ homes and begin seeing the world through independent eyes. A classic example is Hillary Clinton, who attended Wellesley College and Yale Law School at the height of the Vietnam War, and in rejecting the war came to reject her father’s right-wing Republicanism as well. Similarly, Rubio’s generation of Cuban Americans entered adulthood as the Cold War was drawing to a close, which helps explain why anti-Communism does not dominate their political outlook in the way it does many of their parents’.

In American Son, however, Rubio roots his political identity not in incipient adulthood but in childhood. His grandfather, a Castro-hating shoemaker named Pedro Victor Garcia who left Cuba in 1956, “was my mentor and my closest boyhood friend,” he writes. As a child, Rubio writes, “I boasted I would someday lead an army of exiles to overthrow Fidel Castro and become president of a free Cuba.” Garcia loved Ronald Reagan’s militant anti-Communism. Rubio writes, “Reagan’s election and my grandfather’s allegiance to him were defining influences on me politically. I’ve been a Republican ever since.” Rubio’s defining political influence, in other words, occurred when he was 9 years old.

Why didn’t Rubio’s views evolve as he entered adulthood, as happened for so many of his peers? Perhaps because as an aspiring politician, his success depended on cultivating the older, more hawkish Cubans who dominated Miami-Dade County. In his mid-twenties, Rubio interned for Representative Ileana Ros-Lehtinen, a Cuban-born politician two decades his senior who once publicly called for Castro’s assassination. After law school he went to work for a firm led by Al Cardenas, another Cuban-born Republican power broker a generation older than himself. Rubio won his first elected office, as a city commissioner in West Miami, in part by securing the support of Rebecca Sosa, the city’s popular Cuban-born mayor. In his biography The Rise of Marco Rubio, Manuel Roig-Franzia quotes Sosa as saying that Rubio “started talking about everything he learned from his grandfather and I was just blown away.”

I’m not suggesting that Rubio’s opposition to normalization with Cuba is insincere. Good politicians are capable of believing deeply in the stylized life narratives they construct. And Rubio’s tale of an American son’s fidelity to his immigrant-born parents and grandparents resonates far beyond Cubans and the GOP. But there’s a fine line between honoring an older generation’s experience and being captive to it. John F. Kennedy distinguished himself from his more parochial Irish-American father by abandoning the anti-English bias that led Joe Kennedy Sr. to oppose American entrance into World War II. Jimmy Carter came to represent the “New South” by both taking pride in his Georgia heritage and rejecting his own father’s segregationist views.

Obviously, Rubio’s grandfather’s hostility to Castro is far more legitimate than Kennedy’s father’s isolationism or Carter’s father’s segregationism. But by refusing to see Cuba policy anew, in light of his generation’s very different historical experience, Rubio is honoring his past rather than creatively imagining the future.

Michael Kinsley once called Al Gore “an old person’s idea of a young person.” It wasn’t a compliment back then. And it won’t serve Marco Rubio well right now.