“It is a common phrase right now that ‘America has institutions,’” Ms. Tolokonnikova said. “It does. But a president has power to change institutions and a president moreover has power to change public perception of what is normal, which could lead to changing institutions.”

As if to make her point, later that day the informal Trump adviser Corey Lewandowski declared that The New York Times’s executive editor, Dean Baquet, “should be in jail.” In October, The Times published an article about leaked pages from Mr. Trump’s 1995 state tax returns.