Most countries in the world have political parties. I don't however understand what their purpose is. For example, take the hypothetical question of "should we build this dam?" I would expect that this would be discussed in parliament, some lawmakers will say "yes" and some will say "no", the matter is put to a vote, the majority wins, and a decision is made.

However what I usually see happening (at least it's represented as such in the news) is that all the lawmakers don't vote according to what they feel about the motion, they vote according to the party line. It's normal that some, perhaps even most, lawmakers from that party will agree with the party line - that's why they're in the party after all. But it's also natural that there will be a few that disagree, at least on some more controversial motions. If everyone votes according to the party line, then there's effectively no individuality.

The other issue is, if everyone is just going to vote along the party line, what's the point of even having members of parliament? One could easily program robots to vote in their place.

According to Wikipedia there're indeed countries where all lawmakers are independents (Kuwait & Niue). Why isn't this more widespread? Why do other countries use political parties - what is the advantage?

  • 3
    Niue has a population of <2000. And, while Kuwaiti law does not recognize political parties, numerous political groups function as de facto political parties in elections, and there are blocs in the parliament. en.wikipedia.org/wiki/Kuwait#Political_culture
    – Thomas
    Commented Nov 21, 2018 at 3:56
  • At least in Canada, it's very unusual (but not unheard of) to have political parties at the municipal level.
    – Roger
    Commented Nov 21, 2018 at 15:07
  • 1
    to celebrate political events.
    – SCFi
    Commented Nov 21, 2018 at 15:15

7 Answers 7


Based on your comments on other answers, I believe the thing that you're missing is that on any given subject, some individuals feel stronger than others, and votes happen in sequence. Reducing things down to the simplest one which demonstrates my point, lets have a legislature with 3 members, A, B & C, voting on two issues, whether to build a dam and whether to build a road.

  • A supports the dam, but doesn't care about the road.

  • B supports the road, but doesn't care about the dam.

  • C dislikes both the road and the dam.

If everyone votes with their true position, both votes are tied, but if A & B conspire to vote yes for both options, they get what they want. However, if the road vote is second, then how can B know that A will stick to her position? Parties are one answer to this, by forming long term, stable partnerships between different groups, which are bound tightly together by an external structure (climbing the party hierarchy requires supporting the party ideology). And because people staying with their party can win more votes they care about than from the outside, they tend to persist.


Although many states now constitutionally recognise political parties, their historical origin is an evolution from informal coalitions and factions.

Initially, there would be many loose and overlapping groupings representing different combinations of views - a candidate in the English Parliament might say he was "pro-Catholic" and "anti-slavery", and those lucky enough to have a vote could support him or his opponent based on those views. Gradually, this consolidated into the "Whigs" and "Tories", both initially insults applied to opponents, but eventually the names of formal parties.

There are several reasons that this evolution happens:

  • During a national or constitutional crisis, one issue will dominate political discourse; the view on this issue will become the defining feature of each candidate.
  • Deals are made between politicians of the form "if you support me on issue X, I'll support you on issue Y". These may then generalise into "if we work together, we can achieve grand aim Z".
  • Where executive power resides in parliament (e.g. in the Westminster system which originated in England), the Government needs to agree on strategic directions, preferably ahead of elections. Even in systems with a separate executive branch, such as the USA, committees need to be formed which represent the wider house, and parties provide a formula for this representation.
  • As suffrage increases, the personal connection of representatives to their electors reduces, and the importance of broad, easy-to-digest manifestos increases.
  • Nationally or regionally orchestrated campaigns can make more effective use of resources than many small independent campaigns.

Once parties are established, it is very hard for an independent candidate to compete: even if they're elected, they have no natural allies to push their agenda through. The system then becomes entrenched, and may well reduce to two huge party machines, as in the USA.

This doesn't mean that all party members are (necessarily) robots who follow the party line, because they can both influence their party's policies, and occasionally distance themselves from them. What it does mean is that each politician does not maintain a detailed position on every issue, trusting those in their own party to produce a reasonable policy.



A single politician is unlikely to be able to achieve much. However, if a group of politicians works together, they can achieve more. For example, by gaining a majority in a legislative chamber they can pass bills.

It is also easier to campaign as a party than as individuals because much of the campaigning occurs on a national stage, rather than being local issues. Many voters may not know their local candidate, but will know the parties. It also allows campaign resources to be focused on competitive districts.

Of course, the challenge of forming a party is needing to agree on a coherent policy platform. But, if they can't agree within one party, how could the legislative body as a whole agree on bills?

  • Well if there are, say, 99 members of parliament and there are only two options yes or no, then one side is always going to gain a majority right? And while many voters may not know their local candidate but know the parties, having parties still means that there are only two options to vote for which may not represent the full spectrum of political beliefs, e.g. if a person believes in the need for a strong military and also believes in inclusiveness, do they vote Democrat or Republican?
    – Allure
    Commented Nov 21, 2018 at 12:00
  • @Allure You have over-simplified your example to the point that it's meaningless. In reality, there are many more than two options - to use your dam example, how big is the dam, what is its budget, who will maintain it, how will displaced people be compensated, and so on, and so on. The final vote will be "yes" or "no" to some proposed set of answers, but that proposal will be a compromise negotiated in order to win a majority. It's that negotiation which is easier if groups of politicians agree to work together on broad policies, rather than all trying to have input on every detail.
    – IMSoP
    Commented Nov 21, 2018 at 15:02

There are multiple questions to address here:

Why do we have political parties?

Because they are effective.

A political party, loosely defined, is a group of similarly minded people that have an agreed upon agenda or goal in government.

By agreeing to cooperate with a group of people, there is more capability in getting the job done. This is not unique to political parties. Other answers have covered how the cooperative aspect is beneficial.

Another element to why we have parties is public perception. People have a tendency to agree with someone that many other people also agree with. By organizing a group behind fewer concepts, you grant that concept more authority by claiming the people of the party back it.

Another reason, safety. Political parties are often sought as a means for protection. They are able to help defend each other from aggressors.

The other issue is, if everyone is just going to vote along the party line, what's the point of even having members of parliament? One could easily program robots to vote in their place.

This question's root comes from an entirely different concept as to why the party exists in the first place. Voting party lines is common, but not absolute. In many cases in many governments there are examples of individuals voting against the party.

Here, the point is to advance an agenda you agree with or prevent something you disagree with. A political party frequently has a member or group of members that typically try to convince everyone else in the party it is in their best interest to vote a certain way on a topic. In the US, this is typically called the Whip. For that job, it is also about tallying the vote counts prior to the vote.

This is all part of the party strategy. If a party doesn't consistently vote together, it is not viewed as a cohesive or strong party, so it may be difficult for it to gain power.

According to Wikipedia there're indeed countries where all lawmakers are independents (Kuwait & Niue). Why isn't this more widespread? Why do other countries use political parties - what is the advantage?

A common binary spectrum used to describe lawmakers would be to place them on a scale of conservative or liberal, however they are defined. While this binary spectrum may not be very accurate in many instances, it does allow some level of measuring candidates. Even in instances where every lawmaker is independent, the are publicly associated with groups of ideals or values.

This naturally lends itself into creating political parties. Where a candidate is able to leverage those associations.

Having everyone independent in large communities leads to several potential problems. In smaller governments, this may be acceptable, but might not win favor over the many advantages parties afford.


Let's imagine a country where the only political question had to do with your color, for example the color of the flag. Now lets say that there are four candidates Purple, Lime Green, Olive Green, and Violet. 39% of the voters prefer Purple, 31% Lime Green, 29% Olive Green, and 1% Violet. If we hold a general election with all four candidates, Purple wins.

But if voters get together and form a Green party and a Purple Party, things change. In the primaries, Purple and Lime Green win their respective parties nomination. Then you have a 2-cadidate general election, and all the Green voters vote for their party's candidate. Green's candidate (Lime Green) wins with 60% of the votes.

Of course its more complicated than that, but the idea is that by voting with others having similar preferences, it can improve the chances that the 60% get something close to their favorite color.

The oldest political parties in the world are the Tories and Whigs, both formed in 1678. The primary issue that drove this was Anti-Catholicism in the UK, and a bitter controversy about the line of succession, this resulted the Exclusion Crisis.

  • Thanks for the answer. This doesn't exclude the voters forming temporary coalitions though, so e.g. Alice could back Bob with a green flag, but disagree with building a dam - in the modern parliament, it seems like Alice and Bob always vote for the same thing if they're in the same party.
    – Allure
    Commented Nov 21, 2018 at 5:48
  • Yes. There are several ways this outcome could happen, for example a non-partisan top-two primary. But there is no perfect voting system and all those other voting systems probably were not well understood when the party system formed. Commented Nov 21, 2018 at 16:30
  • 1
    @Burt_Harris I would put it more strongly than that: there was no singular event when "the party system" formed; rather, parties naturally emerge as a convenient and effective strategy, in pretty much any voting system.
    – IMSoP
    Commented Nov 21, 2018 at 17:49
  • @Burt_Harris Is that true universally though? Are, say, Spanish political parties also inspired by the Whigs and Tories? Or is the slow formalisation of factions into parties a natural progression as a parliament matures?
    – IMSoP
    Commented Nov 22, 2018 at 9:26
  • 1
    @Hoki If you're talking about the UK, there is no direct link between votes or Parties and the Prime Minister. The Prime Minister is appointed by the monarch at the recommendation of Parliament; that means having the support of the majority (not just a plurality) of MPs; and once Parties are established, such support will likely fall along Party lines. In 2010, it was not definite that Cameron would be PM until he had negotiated a sufficient coalition that more than half of MPs would support him; similarly, in 2017, May had to negotiate the support of the 10 DUP MPs to secure the position.
    – IMSoP
    Commented Dec 27, 2022 at 15:45

Why do people form companies instead of doing business as individuals? The reasons for having political parties are similar.

Other answers have already described two major reasons. Stable coalitions with like-minded individuals give a representative more influence. There are economies of scale to winning elections. Yet there is also a third major reason the others have not mentioned: division of labor.

Societies are complex. No single individual understands all the issues a parliament deals with. There are not enough hours in a day for a representative to read and understand all the materials they receive in their legislative work. In order to deal with this complexity, different representatives specialize on different topics, and the rest of the party generally trusts their judgment on these topics. This way, a representative can have some idea of what they will be voting on, without giving away too much power to their staff or unelected officials.


Values. Simple as that. Parties represent values and values are personal things. However, legitimacy is also important. So parties need to be unified. They need to appear strong, because if they appear strong and unified, it gives the impression that they can accomplish things. That's why parties exist and why people vote along party lines. It's about getting things done and the way you do that is demonstrate strength though unity. Because unity implies strong management and cohesion. It demonstrates that everyone is on the same page.

This isn't a unique idea. Businesses want this all the time. They want strong group unity. They want people to come together and fix problems. A unified group with a weak solution is better than a a strong solution and a group in discord.

This is why parties vote along party lines. Because working together, even in the wrong direction, looks better than everyone just going their own way.

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .