The invitation set off an uproar, with many people complaining that Ms. Manning was a traitor to the country and should not be honored with a Harvard fellowship. Just after midnight Friday, the Kennedy School dean rescinded Ms. Manning’s fellowship, prompting another round of complaints by others who saw a vaunted institution buckling under political pressure.

In inviting people from all ideologies, including some considered odious to the opposing side, Harvard had hoped to provoke discussion across party lines in a campus setting that would keep hyperpartisanship at bay.

Others on the visiting fellows roster include: Sean Spicer, President Trump’s former press secretary; Corey Lewandowski, Mr. Trump’s former campaign manager; and, from the media world, Joe Scarborough and Mika Brzezinski of MSNBC.

But the ivory tower ideal of the campus as an arena for the free exchange of ideas — one being challenged at colleges across the country — exploded over the Manning episode. And Harvard is being attacked not only by conservative commentators but by the very government-media establishment that the Kennedy School depends on and has a revolving-door relationship with.

One of the classes offered here is called “From Harvard Square to the Oval Office.” The dean of the school, Douglas W. Elmendorf, is the former director of the Congressional Budget Office.