This column is not in the business of forecasting recessions, based on inverted yield curves or any other form of augury. But when enough credentialed auguries suddenly think one might be possible, it seems prudent to speculate about the consequences if they turn out to be correct. So let’s imagine what might follow if, sometime this winter, our post-2008 economic expansion finally ends.

First, the easy part: Donald Trump loses re-election. It will be ugly and flailing and desperate and — depending on recession-era geopolitics — potentially quite dangerous, but there is no way a president so widely disliked survives the evaporation of his boom. The rules of politics have changed, but they haven’t been suspended. Polarization will keep Trump from being defeated in a landslide, but not from being beaten handily, and in a recession the Democrats can nominate any of their candidates and expect to evict the president with ease.

What comes next? In Washington, the centrists get a surprising opportunity. Blamed and written off by left and right alike, a Trump defeat would give the capital’s dwindling band of dealmakers and moderates another chance to govern — because even if it’s Elizabeth Warren or Bernie Sanders in the White House, it’s still going to be red-state Democrats and blue-state Republicans holding the balance of power in the Senate. The left-wing revolution won’t be canceled, exactly, in those circumstances, but it will be postponed till after 2022 or 2024; in the between-time, the people who once pined after comprehensive immigration reform and deficit commissions may get a (last?) chance to prove their critics wrong.

Meanwhile, the right will have to decide whether it wants to be an opposition or an alternative. With a bad economy and a liberal Democrat in the White House, conservatives could well return to the scripts of the Obama era, rediscovering (with whatever absurd hypocrisy) the perils of deficits and big spending, and defining themselves entirely against whatever bargains the center-left attempts to make. But if the G.O.P. is reduced to a white working-class base at a time of increasing economic pain, there will also be incentives for Trump’s would-be successors to flesh out his populism rather than abandoning it. This will be the ground on which the next Republican civil war gets fought no matter what, but how long a recession lasts and how it gets interpreted will determine whether a serious post-Trump conservative populism is inevitable or stillborn.