Jeff Sessions lasted in his post as attorney general for 18 hours after the Democrats took control of the House of Representatives on Election Day. His ouster, anticipated for months, may finally allow the president to fire Special Counsel Robert Mueller without consequence. Even for a country now accustomed to whiplash, it was a head-spinning day: the promise of national civic renewal followed by yet another potentially catastrophic threat to the health of American democracy.

The juxtaposition revealed the central challenge of this political moment. Despite the Democrats’ victory on Tuesday, the midterms showed that Trumpism has a real political constituency—and that the geographic distribution of that constituency combines with the structure of American government to provide the president with protection from a friendly Senate. The struggle to uphold the rule of law and to call Trump to account is ultimately a political fight with no easy shortcuts. It’s a hard, bitter slog, with a long way yet to travel.

Continued Republican control of the Senate was widely expected going into Election Day, but for the GOP to keep its hold on the House would have risked plunging the United States further into a crisis of democracy, emboldening a president already given relatively free rein by a friendly Congress.