Reince Priebus, normalizer-in-chief

For his part, Bannon has undertaken an incendiary mission over the years to upend the G.O.P. “establishment,” no one more so than Ryan (“a total and complete sellout of the American people,” Breitbart once declared, referring to Ryan’s stewardship of House appropriations). Bannon could occupy something of a mysterious Svengali role in the tradition of presumed all-powerful presidential whisperers like Karl Rove (for George W. Bush) and Valerie Jarrett (for Barack Obama). Both Rove and Jarrett represented wild cards in their respective White Houses and regular thorns in the sides of the various chiefs of staffs with whom they served.

But one notable difference is that neither Rove nor Jarrett made it his or her goal to obliterate the establishments that their presidents were trying to fold themselves into; nor did either have close ties to fringe elements of their parties, as Bannon has to the so-called alt-right and its main platform. Breitbart has been described as a “white ethno-nationalist propaganda mill” by the Southern Poverty Law Center. The site has posted articles linking undocumented immigrants to disease, declared in a headline that “Birth Control Makes Women Unattractive and Crazy,” promoted the Confederate flag (“Hoist It High and Proud: The Confederate Flag Proclaims a Glorious Heritage”) and referred to Gabby Giffords as “the Gun-Control Movement’s Human Shield.”

Bannon, who has tried to play down the most extreme elements of the alt-right in recent days, nonetheless viewed Trump as a kindred provocateur — a feeling that appears mutual. In one form or another, Priebus will try to integrate his establishment orientations with these disruptive forces operating all around him. Back during the campaign, Priebus used to refer admiringly to Trump as “an earthquake in a box.” In a separate conversation (and metaphor), he described his challenge to me as keeping Trump inside “the funnel.” Presumably this meant keeping him directed and contained, easier said than done, but still fascinating — and somewhat entertaining — to watch unfold in the campaign.

But with the presence of Bannon and the weight of Trump leading a nervous and divided nation, the challenge in the White House is considerably less entertaining to contemplate.