No two democracies are built the same way. A few basic design choices, combined in different ways, produce the wide variety of democratic systems we see today.

Direct and representative

In direct democracy, citizens make decisions themselves. Pure direct democracy is rare at the national level, but strong elements survive. Switzerland holds several national votes a year on laws and constitutional changes, and citizens can force a vote by gathering signatures. Two small Swiss cantons still hold open-air assemblies, and many New England towns hold yearly town meetings where residents vote on budgets.

In representative democracy, citizens elect officials who make most decisions. Nearly all national governments work this way, sometimes with added direct tools such as referendums.

Parliamentary and presidential

This choice concerns how the head of government (the person who runs the executive branch) is chosen and held accountable.

• In a parliamentary system, such as the United Kingdom, Germany or Canada, voters elect a legislature, and the government is formed from it. The prime minister stays in office only while keeping the confidence of a majority in parliament. If that majority withdraws support, the government falls, without waiting for a fixed date.
• In a presidential system, such as the United States, Brazil or Mexico, voters elect the president separately from the legislature, for a fixed term. The legislature cannot remove the president simply for losing its support; removal requires a special process such as impeachment.
• Semi-presidential systems, such as France, combine an elected president with a prime minister who needs parliament's support.

Parliamentary systems are praised for flexibility and clear responsibility: the governing majority can act and can be removed quickly. Presidential systems are praised for stability and for giving voters a direct choice of leader, with strong checks between branches. Critics of presidentialism, such as the political scientist Juan Linz, warned that two separately elected branches with fixed terms can deadlock, with no easy way out. Critics of parliamentarism point to unstable coalitions and governments that fall often.

Federal and unitary

This choice concerns how power is divided across territory.

• In a federal system, such as the United States, Germany, India or Australia, the constitution divides power between a national government and regional governments (states, provinces or regions). Each has its own protected areas of authority.
• In a unitary system, such as France or Japan, the national government holds ultimate authority and local governments have only the powers it grants. Some unitary states, like the United Kingdom, have devolved significant powers to regions while keeping final authority at the center.

Federalism lets diverse regions govern themselves and test different policies, but can create inequality between regions and confusion about who is responsible. Unitary systems are simpler and more uniform, but can feel distant to people far from the capital.

Liquid democracy

A newer idea, made practical by the internet, is liquid democracy. Each member can vote directly on any issue, or can delegate their vote to someone they trust, and can choose different delegates for different topics. Delegations can usually be passed along (if you trust Ana and Ana trusts Ben, your vote may reach Ben), and can be taken back at any time. Some political parties and online communities have experimented with software built on this idea.

Supporters say it combines the expertise of representation with the control of direct democracy. Critics worry that a few popular delegates can gather enormous power, that it is hard to see who holds whose votes, and that the secret ballot is difficult to protect. The term delegative democracy is sometimes used for this model, but be careful: the political scientist Guillermo O'Donnell used the same term for something different, a system where an elected president governs with few checks between elections.

Worked example: a crisis in two systems

Imagine a sudden scandal: a head of government is found to have misled the public about a major policy, and their own supporters are outraged.

In a parliamentary system, members of the governing party can call a vote of no confidence or simply choose a new leader. Within days or weeks, a new prime minister may be in place, often without a general election. The crisis is resolved quickly, but voters had no direct say in the change.

In a presidential system, the president serves a fixed term. Unless the misconduct meets the standard for impeachment and enough legislators agree, the president remains in office until the next election. The legislature may block the president's proposals, leading to deadlock. The system is more stable, but a damaged leader may stay in power for years.

Now add a third design: a liquid democracy community, such as an online cooperative. Members who had delegated their votes to a disgraced leader can simply take them back, instantly. Power shifts within hours. But if a few charismatic members had gathered thousands of delegations, a single persuasive speech could swing the whole community just as quickly.

No design is best in every situation. Each one decides, in advance, how quickly power can change hands and who gets to change it.