I was in Spain this past week for a pair of political science conferences. My visit came soon after an election in which two new parties emerged: Podemos (leftist and innovative in how it engages voters) and Ciudadanos (center-right and also somewhat innovative). Naturally, many conversations turned to these parties and to party competition in general. I return feeling jealous of multi-party systems because they present opportunities for civic innovation.

The United States has had the same two parties for 155 years because we use single-member districts. A third party that at first attracts less than 50% of the vote in every district wins no seats at all and can’t get off the ground. Also, despite our important regional differences, we have essentially one national public sphere, so regional parties don’t arise to win majorities in their own areas. A case like Bernie Sanders from Vermont is anomalous and arguably getting more so. In 2012, voters chose straight Democratic or Republican tickets more than at any time since 1952.

If the question is how best to represent the public, a two-party system is not intrinsically worse than a multi-party system that emerges from proportional representation. Arrow’s Impossibility Theorem proves that no system is really ideal in that respect. If voters are given many choices, no party is likely to gain a majority, and then either a minority leads the legislature or there must be some horse-trading to produce a majority coalition that voters did not deliberately select. In a two-party system, the people choose the majority, but only because their choice has been restricted.

The problem, then, is not that our system is especially unrepresentative but that certain kinds of innovations and opportunities are blocked. In the US, as everywhere else, people form new groups that reflect their views, not only about how the world should be but also about how they will relate to each other and make decisions. These groups vary enormously, from terrorist cells led by charismatic clerics to New Left assemblages in which all the decisions are made by consensus and anyone can enter or exit at will.

Let’s assume that some groups are better than others and, indeed, that a few are very good. Because they start as small associations, they cannot directly govern at large scales. They need more than ideals and ways of interacting with their own members; they also need strategies for influencing law, government, and the economy. In a word, they need leverage.

In a system that encourages new parties to form and compete for power, one powerful form of leverage is available. The intellectuals and grassroots activists who emerged from the Occupy-style social movement in Spain naturally formed a political party, Podemos, to reflect both their views of national policies and their ways of self-organizing. It remains to be seen whether they can remain faithful to their origins as a social movement now that they are a formal political party with seats in the legislature and control over some cities and provinces. But that path was available and they took it.

Innovation is not intrinsically good. ISIS is highly innovative. But it is crucial that a political system allows new entrants: not just individuals who haven’t run for office before, but new kinds of people with new ideas. Otherwise, it hardens into an oligarchy.

In the US, people still come together in all kinds of movements and networks within civil society. #BlackLivesMatter, Occupy, and the Tea Party are just some of the high-profile recent examples. If you looked more closely, you would see many more of these groupings, some with narrower ranges of issues, less explicitly political agendas, or more idiosyncratic organizational forms.

Such movements and networks often talk about scale and leverage. In the US, they think first about trying to change public opinion, influence the media, or recruit new members. Occasionally, they also talk about running candidates for office. In the Tea Party’s case, they have used primary campaigns to obtain some influence over a major party. But they cannot gain momentum by launching new parties of their own and coming before the electorate with their own platforms, leaders, and organizational structures. And this is why the discussion of large-scale strategy is so frustrating in the US.

This problem is going to be especially acute for the left for the next few years. On the right, the Tea Party and libertarian movements have found ways to compete within the GOP. The seemingly open and competitive Republican primary campaign means that conservative activists have a strategy for leverage: pick one of the candidates. Although only two or three of the Republican contenders have plausible chances, the competitive start of the campaign makes the GOP presidential primary look like an opportunity for diverse activism on the right.

On the Democratic side, the unprecedented dominance of Hilary Clinton means that supporting a campaign is really not a way to innovate in politics. Clinton and her staff can innovate if they want to. As a voter, you can support Clinton if you agree with her more than with the Republicans. Otherwise, you must innovate outside of formal politics.

I exaggerate because there are other Democratic presidential candidates, and more could enter. But the lack of a candidate who reflects (for instance) any of the recent ferment about race and racism is a symptom of our situation.

My point, again, is not that our elected leaders fail to represent the people. Some Democratic Members of Congress represent predominantly urban African American communities and are reasonably in sync with their constituents. The point is rather that no one–other than established party leaders–can seriously innovate within electoral politics on the Left for the time being. I predict that will produce a lot of frustration unless someone can figure out an alternative form of leverage.

See also community organizing, community-engaged research, and the problem of scale; beyond small is beautiful; leverage as a moral issue; and “En EE UU, el populismo es bastante razonable.”