Why Parties?

Why Parties?

If democracy seems inconceivable without political parties, it is reasonable to think that the way political parties are organized affects democracy as well.

In a blend of American politics and its history, social choice theory, and comparative politics, John Aldrich (Duke University) addresses in his book "Why Parties?" two questions that are at the center of academic debate in Political Science:

  • Why do politicians decide to run with parties instead of as stand-alone candidates?
  • How has the organization of parties changed across history? And why have we ended up with a polarized situation in the US?

Though the book is best suited for an audience familiar with the scholarship in social choice theory and the new institutionalism, John writes extremely clearly and makes scientific research understandable for the broader public. In particular, the answers he provides to the those questions and the implications he draws are quite revealing.

Let’s dive in!

Why Do Politicians Join Parties?

The easy answer: Because politicians are rational actors and use the party to achieve their interests.

But this is a sort of begging the question, isn’t it? So, we need to go one step further: Why do politicians join parties instead of alternative associations to advance their interests?

Political parties are institutions that people typically rely on to represent their vision of the world. Political parties are associated with a 'brand name,' which essentially consists of a set of policies, ideologies, and perspectives on how the world works and should work. This close association between a party and a worldview provides voters with an informational shortcut.

This means, 'I know that this party represents what I like, so I don't need to know everything about the candidates. I'll just vote for the candidate in the party I favor, confident that they will advance the party's vision of the world.'

Political parties are highly useful for voters because they simplify the process of choosing a side and casting a vote. In this sense, political parties help solve the problem of mobilization and collective action by making it much easier for people to access information about politics and vote.

On another note, but still related to mobilization, political parties have resources and benefit from economies of scale. They attract campaign funding from philanthropists, funds, entrepreneurs, and institutions because of the potential rewards they can offer if they win the elections. They also mobilize activists across the entire country.


Politicians affiliate themselves with parties or create parties to benefit from mobilization, economies of scale, resources, and ideology.

“Political parties are “solutions” for furthering particular goals.”

How Have Parties Changed Across Time?

In the beginning, the relationship between parties and candidates was one where the party was more important than its candidates. The prevailing idea was that parties had to be 'more important than the individuals within them' to prevent any one person from being tempted, through the accumulation of too much power, towards corruption or tyranny.

However, we find ourselves in a situation where specific candidates now dominate the party, and voters support a party primarily for a particular candidate.

What led to this shift?

  • The introduction of primaries,
  • The selection of more extremist candidates (e.g., Goldwater in 1964 and McGovern in 1972), and
  • New technology

have transformed the electoral landscape into a candidate-centered era. Following the introduction of primaries, party candidates became subject to the influence of ideologically committed factions (where being more extreme during primaries could translate to a slightly less extreme policy platform during national elections). This shift pushed more moderate candidates away from the party. The public recognized this change, and reacting accordingly.

Simultaneously, new technologies such as social media have allowed individual candidates to build their own audiences and support bases independently of parties. Likewise, expertise, which historically centered on knowledge of local politics and the ability to form coalitions with various state and local political machines, has evolved into a field focused on public opinion surveys, a task that can be easily conducted by entities separate from political parties. Today, political knowledge is "available for hire."

Take Home Lesson

As a result, today's politicians often affiliate themselves with and create political parties primarily for the sake of the party's 'brand name.' This 'brand name' offers voters informational shortcuts and encourages them to participate in the electoral process. Politicians do not necessarily depend on the party's resources and expertise.

In this context, individual candidates have become more significant than the parties themselves as a whole

My Take Today

The uncomfortable lesson from the book is that parties (or politicians) are the causes of political polarization. This means that parties provide (or impose) an ideology on voters instead of responding to their ideological demands. Voters are responsive to politicians' visions of the world, and not the other way around. Given the significance of the brand name that the political party provides, it is rational for politicians to use the party to achieve their goals.

So, I think we should really ask ourselves one question:

Is polarization a genuine result of democracy? Is polarization endogenous in all democratic systems?

If it is rational for political actors to gradually polarize their platforms, can we consider polarization a natural feature of democracy rather than a degenerated possibility? If not, as I hope, what can we do to prevent politicians from dividing us? How can we make politicians more responsive to our political preferences?

And how can we develop political preferences regardless parties' ideologies? What are alternative competitive visions of the world that we may have? Traditions? Philosophies?