Last week, former Vice President Joe Biden was compelled to renounce the Hyde Amendment, which until relatively recently had marked the only durable truce in the abortion wars. A California audience booed John Hickenlooper—the former governor of Colorado and another Democratic presidential hopeful—nearly off a stage for observing what everyone understood as indisputable five minutes ago: “Socialism is not the answer.”

Welcome to what is becoming the Democratic Party’s de facto slogan for the 2020 campaign, borrowed from the Jacobin French by way of the Russian revolutionary Alexander Kerensky: “No enemies to the left.”

The issue is not simply that Democrats are moving left. Let progressives propose as they wish and defend as they must. The danger of Democratic self-immolation arises not from where the party is headed but rather from how it is getting there: an ideological auction in which the most extreme position necessarily wins. Democrats are marching to the left not on principles they can articulate but rather because no candidate dares stand to anyone’s right.

Accurately predicting that the French Revolution would consume itself, Edmund Burke grasped the dynamic: Members of the French National Assembly had become “bidders at an auction of popularity.” The result, he lamented, was that “if any of them should happen to propose a scheme of liberty, soberly limited, and defined with proper qualifications, he will be immediately outbid by his competitors, who will produce something more splendidly popular.”

Is there a more perceptive description of the Democratic Party’s recent behavior in opposition? The preferred response to the Trump administration’s immigration policies is not simply to end family separation and reform the asylum and visa processes but also to “Abolish ICE.” Protecting and restoring President Obama’s health care reform, which preserved private insurance, is not enough: Endorsing “Medicare for All” is nearly a price of entry for Democratic presidential candidates.

Affordable college education, long a staple of the Democratic agenda, is now free college education. A noble commitment to civil rights gives way to rigid identity politics. An equally honorable record of building a social safety net has given way to in calls for an ill-defined—if fervently professed—democratic socialism, replete with anachronisms like “late-stage capitalism.”

Their proponents, again, can defend these positions. But thus far the inflationary dynamic of the party is forcing the candidates to outdo one another on partisan extremes whether they wish to go there or not. This dynamic is as inherently hostile to moderation as an auction is to low prices.

Yet moderation, we are told, is a political loser, while hard-left policies that could inspire new voters have not been tried. As to the former claim, nothing offers a sharper contrast with President Trump, and Americans, having been on a political bender, might kindly receive a call to sobriety that is leavened with moderate policies. Adherents of the latter proposition are much like the doctor who, his medicine having nauseated the patient, says the real problem is that the dose was too low. There is simply no empirical evidence that a fundamentally centrist country is teeming with uninspired progressives who do not vote.

Moderation is different from a geometrical centrism that splits the difference between wherever the parties happen to stand at a given moment. That is rootless and arbitrary. It is no match for President Trump’s inflammatory populism. That does not mean Democrats need a more inflammatory populism to win.

When Burke praised moderation, he meant that moderate positions should be strongly held and philosophically defended. When statesmen become “flatterers instead of legislators” by auctioning off policy to the most extreme bidder, however, “moderation will be stigmatized as the virtue of cowards; and compromise as the prudence of traitors.” Centrism may be empty as an end to itself. Substantive moderation has much, in all moments but especially in this one, to commend it.

That is not a call to abandon principles. Both liberal and conservative positions can be moderately held if they are touched by what Judge Learned Hand called “the spirit which is not too sure it is right.” For Burke, humility and therefore moderation was the product of “a moral rather than a complexional timidity”—moral because it arose from a substantive respect for the limits of human reason. Humility does not seem to be restraining the resistance just now.

This leapfrogging, race-to-the-left mentality is partly a condition of opposition, which often entails outflanking those tasked with actual governing. Certainly Republicans, especially in their intervals away from power, have been known to outbid one another on the right.

It is nonetheless worth wondering whether hostility to moderation is endemic not just to opposition in general but to progressivism in particular. Daniel Patrick Moynihan, a staunch New Deal liberal, observed the tendency of the “chiliastic” New Left in the 1960s and early 1970s to “resist social changes which, however profound, [were] not perceived as somehow ultimate.” The particular problem, he continued, was that that such demands could produce “not merely resistance to social betterment, but actual fear of it.”

This is the internal logic of progressivism as opposed to liberalism: If the goal is progress, more is always better, and advocates of limitation and measure are inherently retrograde. But it is also the logic of populism of all stripes. On Moynihan’s account, the politics of both extremes was inherently chiliastic. A conservative politics oriented toward “the Highest Good” brooks little dissent either.

This headlong rush toward the ultimate is the inevitable result of the democratization of nominating processes through primaries in which only the most partisan voters participate. For this, Democrats can thank themselves for being populist before populism was cool. They spearheaded this democratization of primaries in the 1970s and are accelerating it now by minimizing the role of “superdelegates”—party insiders with an interest in winning elections rather than proctoring purity tests—in the Democratic nominating process. Opposition to superdelegates is, in fact, itself a purity test of commitment to the sun-god Democracy.

A faint-hearted centrism is no match for Trump. But a strong-minded moderation can be. Instead, the auction mentality assures that the battle will be fought where the president excels: at the extremes. When it ends, if it does, Democrats will not only have no enemies to the left. They will have few allies to their expanding right either.