No matter the final count in Iowa, it’s clear Sanders is emerging as the front-runner in the Democratic primary. If he does win the nomination, the presidential race will express a uniquely American version of the wider crisis of authority facing representative democracies.

Consider the fact that both Trump and Sanders will be leaders of parties that they did not belong to in any significant way prior to running. They will both lead parties whose major figures and leading apparatchiks did what they could to stop Sanders/Trump. These will be parties to which neither candidate paid the dues of time and effort: parties that they did not rise up in, rendering the normal relationships of mutual obligation and favor-owing more or less inoperative. All of this makes each of these nominees leaders that are far harder for the party to discipline and control. And, further, it is the source of their appeal to major segments of their party.

These will be candidates elected because the gap between the party establishment and its membership has grown so large that one of their greatest appeals is that they did not follow the rules. If Sanders really is nominated, we will have seen the internal revolt of party members and fellow travelers against the party officialdom in both parties, achieved by selecting someone about as far outside the party as possible: a real estate mogul–cum–reality TV host with no political past and purely nominal party affiliations, and a self-proclaimed socialist who had never before run on the Democratic ticket (prior to 2016) and who remained an Independent even after his first run. It’s interesting to ask why this is happening. Why are the parties being taken over by leaders who are not real members of that party?

As various political scientists, most famously Peter Mair, have long pointed out, the capacity of many major political parties to represent their traditional constituencies in a democratic way has been in decline for a few decades. Peter Mair called it “ruling the void” — political elites and their parties retreat from their constituencies, seeking alternative ways of ruling, while their members withdraw their consent in various ways. In some countries, this has taken the form of the collapse of traditional parties (e.g. the French and Italian Socialists), the growth of new ones (AfD in Germany, Podemos in Spain, Front National in France, Lib Dems and UKIP/BP in UK), and the rise of more ad hoc parties as personal vehicles for national leaders (La République En Marche for Macron, various Italian formations like Berlusconi’s Forza Italia/Grillo’s Five Star, Mélenchon’s France Insoumise).

There are important national variations in these developments. But what Mair noticed about all of them was that there was an important decline in party loyalty, increasing distance between leadership and membership, ideological disorganization of existing parties, all symptomatic of the deeper hollowing out of the parties themselves. Where political parties were created to represent segments of society to the state, they had over time become ways of representing the state to society. The more they functioned to limit and control their members and their aspirations, the less they could serve their properly representative functions and the harder it was for members to control their parties.

We are currently watching the American variation of this process take place. If Sanders wins the nomination, he completes the process of outsiders taking over the parties through the internal revolt of the membership. That has necessarily been the American version of “ruling the void.” There have been failed bids by figures like Ross Perot or Ralph Nader, either outside any party or from very marginal third parties, to break through the two-party monopoly in the United States. But these are mostly notable for how resistant American political institutions are to third-party challenges relative to other democracies. In fact, the legal repression of third parties in the United States is enormous, unmatched in any industrial democracy — one of the many intensely undemocratic features of our “democracy.” I would go so far as to say legal repression of third parties has become a fundamental, though relatively silent, feature of our political constitution. (The historical development of that legal repression was documented by Jacobin ’s Seth Ackerman in his 2016 article “A Blueprint for a New Party.” It served as the legal complement to the violent repression of radical elements of the labor and more militant left movements in the twentieth century.)

This legal repression has reinforced the pragmatic, catch-all, anti-ideological character of the major parties, especially the Democrats. Their regional diversity has allowed them to represent very different groups and combine major segments of capital — like finance and tech — with labor organizations. Never seriously threatened by competitor parties on either side, while retaining a regional flexibility, they have become even more sclerotic and distant party organizations. They have been able to take their “base” — e.g. unions and minorities in the Democratic Party — for granted because they can more or less hold them hostage: you can’t outflank us to the left, and the other guys are worse.

On the one hand, this has meant that the two parties suffer an even more extreme version of the internal decay characteristic of the “void” — they do not face the same costs of failure, not quite the same pressures of internal renewal and of creating real lines of accountability and control. After all, they might lose an election, but not lose the political space they occupy; they have no rivals. On the other hand, it has left only one feasible option to those who wish to challenge the two-party status quo: internal colonization or, a variant, destroy the party from within to create political space for a new party.

This has all taken place during the primaries because of a further oddity of the American party system: we don’t have separate processes for choosing party leaders and for electing presidents, one reason why the electoral season is so fucking long. The internal party debates about what their program should be and procedures for selecting leaders are fused to an electoral process. When you add together the internal decay of the major parties, the legal repression of third parties, the amorphousness of party organizations, and the confusions of party leadership contests and national elections, you get a totally overheated and overextended primary in which, now, both parties face internal colonization. This also explains the brittleness of the party response, the mixture of bias, corruption, and incompetence, and the grasping around for a savior, as they face these challenges.

This same development has taken place at the level of the media. While it is often said that technology is destroying the influence and control of the mainstream media, by proliferating sources of news and opinion, I think that is only half the story. The point is also the declining authority of major media outlets to control narratives and shape debate. Think of the failure of nerve by the New York Times in its dual endorsement of Amy Klobuchar and Elizabeth Warren, or CNN’s failed attempt to hype the Warren-Sanders dustup, or wider evidence of declining trust in leading sources of opinion. The freak-out about online aggression by Bernie Sanders supporters is, in part, a reaction to losing control over prevailing mores and the terms of political discourse. So, too, is the anxiety about Joe Rogan saying he’ll vote for Bernie — Rogan, whose eleven million followers is larger than the viewership of all five Democratic debates combined. Given the fairly loose formal structure of the mainstream parties, the media has served a role in shaping and policing the boundaries of acceptable political discourse. They can’t stand the fact that they are powerless both against Trump’s know-nothing vulgarity and Sanders’s Teflon socialism.

The only difference between the Trump effect and the Bernie effect is that, in the end, Trump has ended up ruling as a more or less conventional Republican on the core issues of value to the party — taxes, judges, business regulation — with some departure on matters of trade and a slightly less militaristic posture. The jury is out on what Bernie’s ultimate effect will be, but he represents a far greater challenge to the Democratic Party. He leads a more organized movement far more ready to take over and transform party structures — or possibly break it apart if resistance from the New Democrat/Clinton/Obama wing is too great. Should that happen, the Democrats will have brought it upon themselves and they will deserve it. Having held their own constituencies in relative disdain, held its base hostage, and done everything they could to freeze out and repress the Left, the Democrats left no other choice but what has become the Bernie strategy. Take the party over.

It’s true, the Democrats are caught in a wider process of political decay and transformation reshaping all the industrial democracies. But it is the parties, and at this moment the Democratic establishment in particular, that are responsible for turning this into an internal revolt. I see few signs that they are in any sense aware of the forces they are caught up in and the role they have played in this process. Part of why I support Bernie is that he brings this process to a head, forces out into the open differences that otherwise have been smoothed over. Given the constraints on American party politics listed above, it is unclear to me that there would have been any other way to really test the limits of existing institutions and show the real character of the ruling parties.