Primary season is almost over, and it's no longer too early to try to assess the size of the blue wave building out there in the country. Will it crest too early and then subside, leaving Republicans in control of both chambers of Congress and a majority of governorships? Will the GOP's sea-walls prove sturdy enough to limit the damage, giving Democrats only a thin and vulnerable House majority and falling short in the Senate? Or will the wave continue to build and build, until it swamps all before it?

As of Wednesday morning all three possibilities are still real. Nate Silver's FiveThirtyEight gives Democrats an 80 percent chance of gaining between 18 and 62 seats in the House — a huge range. Larry Sabato's Crystal Ball predicts a race for Senate control that is tantalizingly close for the Democrats, but still vulnerable to reversal; a gain of as many as four seats for either party remains entirely possible. And the gubernatorial landscape — which will have a crucial impact for redistricting in 2020 as well as for building a track record of Democratic governance across the country — is arguably the most interesting of all, with nearly the entire Midwest region (Michigan, Ohio, Illinois, Wisconsin, Minnesota, and Iowa) in play, along with the mega-state of Florida.

The Democrats could be on the verge of a historic triumph — or a historic disappointment. But however large it proves to be, the blue wave is building at the same time the party is loudly and productively debating its own future direction. This debate will only grow louder after Nov. 6, no matter which way Congress goes. Indeed, how the Democrats ultimately choose to frame the election may matter more than the specific details of how it turns out.

Broadly speaking, the Democrats are debating two different narratives of what has happened to America.

According to one view, the Republican Party is fighting a rear guard action against inevitable change, and growing ever more extreme in their efforts to wring electoral victory out of a shrinking coalition. The Democrats' loss in 2016 was due to some combination of bad tactical decisions by a flawed candidate, foreign interference, the fluky appeal of an adept carnival barker. The Democratic Party, in this view, needs to stand for stable, sensible, responsible leadership that can shepherd the country through domestic and foreign trials and not be baited into infighting.

According to the other view, both the rise of Trump and the increasing radicalism of the GOP are in part a consequence of precisely that leadership preference for responsible centrism. A moderate response to the financial crisis left the bulk of the American middle class under water for years, while financial elites recovered rapidly. Health-care reform left many Americans paying more while insurers were subsidized. And on a purely tactical level, staking out the sensible center leaves the other side free to try to move the Overton Window to the right. It's time for Democrats to try some extremism of their own.

I say this is a productive debate, because I see some sense on both sides. I agree with the insurgent left that a major reason why the radical right is on the rise, not only in America but across Europe, is because the economic paradigm which dominated elite thinking since the early 1990s has lost the support of the electorate. The long recession and slow recovery, the perpetual crisis of the euro, the spread of deindustrialization and the yawning growth of inequality all are signs that something fundamental is not working.

But the insurgent left is prone to delusions of its own, none more potent than the notion that victory on its own will bring change, as though the sources of power that lie behind the policies they decry will simply melt away after their triumph. Politics doesn't work like that, and never did, as any historian of America in the 1930s will affirm.

In another sense, though, the debate on the left is a bit blind to the specifics of what has happened to the Republican Party. The rising right is not merely a more extreme version of what had come before, which is why, in Europe, it has manifested in the form of entirely new parties. (And those who idolize Scandinavian socialism should note how far the extreme right has come in progressive Sweden.) Rather, it is oriented around a set of questions that the established parties of left and right had preferred to treat as settled: the nature of the political community itself, and the proper relationship between that community and its leadership.

Democrats do talk about those questions — but usually in the context of subsidiary identities. When an African-American candidate argues that her community deserves representation, that's an appeal to identity, and a perfectly legitimate one. But Americans as a whole also need to feel represented, not necessarily in the sense of having the proper demographic boxes checked, but in the sense of being governed by people they trust and who they believe trust them. Because that's what identity politics ultimately is, whether of the left or right-wing variety: a politics of "who do you trust?"

To some extent, building trust is a matter of Democrats taking their own rhetoric seriously and acting on it. Take political corruption, something the Democrats are rightfully talking about given the orgy of self-dealing centered in the Oval Office. Centrist and left-wing Democrats alike will aver that corruption breeds distrust of government, and that distrust is more ideologically helpful for right-wing populists and anti-government Republicans than it is for the party of activist government. But taking that question seriously means taking it seriously in New York and New Jersey as well, just as taking sexual harassment seriously meant taking it seriously about Democrats like Al Franken.

But it's also about how left-wing policies are framed. The insurgent left is pushing a number of policies — Medicare-for-all, tuition-free college — that can readily be caricatured as "free stuff," and the charge may stick if voters come to think of them primarily as benefits for the poor. But they can just as easily be described as ways of leveling the playing field with the elite: cutting out parasitic insurance companies, or pressuring private colleges to follow St. John's University and get off the seemingly-endless tuition escalator.

Even on as hot-button an issue as immigration, where Democrats rightly see a need to draw a moral contrast with the Trump administration, they also need to speak to a sense of divergent interests between elites and the people. Our willingness to welcome and integrate people of talent from all over the world is indeed a great source of strength for America. But a tacit bargain between business and government that minimizes the clout of working people — whether by making low-wage workers compete with undocumented immigrants or by making professional workers compete with H-1B visa-holders who can't hunt for another job — is a cause of great national friction. It shouldn't be hard for Democrats to talk about reforming our immigration system in a way that genuinely benefits workers, native-born and immigrant alike.

It's become conventional wisdom that, in our polarized era, all you need to do to win is motivate your base to vote. But two parties can play at that game, and when they do — as they did in 2004 and 2012 — the results are generally frustrating for both sides, as trench warfare tends to be. Moreover, even ideologically-committed voters prefer to think of themselves as fighting for their country, not fighting with it.

The only Democrat to win a national popular majority since Lyndon Johnson organized his entire political persona around speaking to — and for — the country as a whole. The next successful Democratic leader surely won't do it the same way — the times, and the country's challenges, have changed. But they'll do it some way, or they won't succeed in building the durable majority they seek.