Photo: Haiyun Jiang/The New York Times/Redux

At first, Maple was by my side. Kirsten Gillibrand’s Labradoodle pressed himself against my legs, happily accepting scratches and offering up a stuffed animal he hoped I would tug from his mouth (I obliged). New York’s junior senator, her once-blonde hair now closer to the white of Maple’s coat, then sat down across from me in her office, ready to explain how cryptocurrency had become one of her most prominent legislative priorities.

It was not an obvious place for her to end up. Two decades ago, Gillibrand won election to…