Beneath a loving re-creation of ’90s New York, Ryan Murphy’s take on JFK Jr. and Carolyn Bessette lacks a big idea and, more fatally, actual feeling. Photo: Eric Liebowitz/FX She’s an enterprising dreamer from modest circumstances. He’s a scion of American royalty. They meet; they circle; they marry. She suffers under the public gaze, he struggles with dynastic expectations, and then they die — tragically, prematurely, she at 33, he at 38 — leaving the public to mourn unrealized potential.