When I met Ms. Raymond-Tolan she was overseeing a group that met weekly to pursue this vein of dissent, and persuade friends and relatives in other states — Maine, New Jersey, Wisconsin — to take the same measures with their own representatives. No staff member for a member of Congress representing an exurb in Wisconsin wants to hear from an orthodontist in Cobble Hill, Brooklyn, about what’s wrong with Rex Tillerson, Mr. Trump’s pick for secretary of state. (Other groups meeting in the same synagogue that evening as part of the Get Organized BK movement, and spilling out of the rooms in which they had been assigned, were targeting women’s health initiatives, or working to develop projects to help schools expand student activism, or talking about how to hold the news media accountable for its coverage of the Trump presidency.) Ms. Raymond-Tolan’s group had already delivered over 2,500 letters to the offices of Senators Kirsten E. Gillibrand and Chuck Schumer, Democrats of New York, asking that they obstruct Mr. Trump’s cabinet appointments.

Outside Mr. Schumer’s prewar building on Prospect Park West in Brooklyn, there have been two actions this month in which hundreds of ordinary people convened, letting the senator, who is the minority leader, know that they are keeping watch, and, by implication, that they will work to install some other Democrat in his place if he concedes, or gets lazy.

Despite the city’s long history of radicalism — during the Progressive movement of the 19th century, in the Communist fervor leading up to World War I, or the social upheavals of the 1960s and ’70s — there is always a strain of skepticism that greets the expression of certain political ideals. Cynicism animates the city as much as hope and conviction. To what extent are activists engaging in self-soothing? To what extent are they merely trying to establish their own relevance? It is always tempting to see the absurdity in theatrical gestures. One woman I met, who had been part of a group devising possible boycotts, announced that the group had come up with the idea of a Dump Trump event. A trash bin would be placed in Grand Army Plaza, in the heart of Park Slope, where people could dispose of their Trump merchandise — shoes by Ivanka, say — which accumulate in brownstone Brooklyn the way collected volumes by Max Weber pile up at Disney World.