4.1 - Electoral Systems and Rules
Electoral rules differ sharply based on regime type. Democratic regimes tend to have structured, stable rules designed for genuinely competitive selection, while authoritarian regimes tend to change electoral rules frequently to advance regime interests whenever convenient.
Electoral Systems by Country
China's National People's Congress is elected indirectly, through a series of local and regional elections where lower levels elect higher levels rather than any direct popular vote for the national legislature, with the Communist Party controlling candidate selection at every stage. This creates an appearance of representation while keeping the party firmly in control.
Only the lowest levels are chosen by voters directly: citizens elect deputies to county and township people's congresses, those congresses elect the level above them, and the provincial congresses (along with the armed forces) elect the roughly 3,000 NPC deputies, who serve five-year terms.
Iran's Majles (290 seats) uses direct election in single-member and multimember districts. A candidate needs at least 20% of the district's vote to win in the first round, and any seats left unfilled go to a second round between the top finishers (in 2024, 45 seats needed a runoff). But the Guardian Council vets every candidate beforehand and can disqualify reformists or opposition figures, there are no formal party structures, and five seats are reserved for recognized religious minorities: Armenian and Assyrian Christians, Jews, and Zoroastrians. It's a hybrid: direct voting, but tightly controlled through candidate vetting.
Mexico's Chamber of Deputies (500 seats) uses a mixed system: 300 seats go to winners of single-member district plurality races (first-past-the-post), while 200 are allocated by proportional representation from party lists. The Senate (128 seats) similarly mixes 96 seats from three-seat constituencies with 32 by proportional representation. Gender quotas applied to party lists have significantly increased female representation.
In each state's three Senate seats, the party or coalition with the most votes takes two and the runner-up gets the third (the "first minority" seat). The 200 PR deputies come from party lists in five large regions, and a party needs at least 3% of the national vote to get any. Parity rules require parties to nominate equal numbers of men and women, with lists alternating between them, and women now hold about half the seats in both chambers (251 of 500 deputies and 64 of 128 senators in the Congress elected in 2024).
Nigeria's House of Representatives (360 seats) is elected directly in single-member districts by plurality, with representatives allocated to each state based on population. The Senate (109 seats) gives each of the 36 states three senators regardless of population, each elected in its own senatorial district, plus one senator for the Federal Capital Territory (Abuja). Two major parties, APC and PDP, have alternated control since the return to democracy in 1999: the PDP held the National Assembly until 2015, and the APC has held it since.
Russia's State Duma (450 seats) uses a mixed system, with half (225) elected from single-member districts and half (225) by proportional representation with a party threshold, but this system has been changed multiple times specifically to benefit United Russia, and electoral manipulation through media control, opposition exclusion, and fraud supplements the formal rules regardless of how they're structured.
The UK's House of Commons (650 seats) uses pure first-past-the-post: every seat comes from a single-member district, and whoever gets the most votes wins, without needing an outright majority. It's a simple, traditional system, used for every Commons seat since 1950 (when the last two-member districts and university seats were abolished), and voters chose to keep it in a 2011 referendum, rejecting a switch to the Alternative Vote 67.9% to 32.1%. The UK's devolved legislatures use different rules: Scotland's Parliament uses a mixed system, Northern Ireland's Assembly uses a form of proportional representation (the single transferable vote), and Wales switched its Senedd to closed-list PR in 2026.
Single-Member Districts vs. Proportional Representation
Single-member districts with plurality voting (first-past-the-post) elect one representative per geographic district, with the candidate getting the most votes winning even without a majority. This system, used in the UK, Nigeria's House, and partially in Mexico and Russia, tends to produce two-party systems (this pattern is known as Duverger's Law), disadvantages third parties, maintains a clear geographic link between representatives and constituents, but can produce disproportionate results where a party's seat share doesn't match its vote share. In the UK's 2015 election, UKIP won 12.6% of the vote nationally but only a single seat, just 0.2% of the Commons, a stark illustration of this disproportionality.
Proportional representation uses multimember districts where several representatives get elected from the same area, with seats allocated based roughly on vote share, often through party lists, sometimes with a minimum threshold required to win any seats at all. This tends to promote multiparty systems, letting small parties win representation roughly proportional to their actual support, more accurately reflecting national voter preferences, though it produces weaker geographic representation and often requires coalition governments. Mexico's 200 PR seats let smaller parties like the Labor Party (PT), the Green Party (PVEM), and Movimiento Ciudadano win representation even without winning individual districts, as long as they get 3% of the national vote, helping sustain its multiparty system. (The PRD, once a major party, fell below that bar in 2024 and lost its national registration.)
Mixed systems, used by Mexico and Russia, combine both approaches: some seats come from district elections (providing geographic representation and tending toward fewer parties) and some from proportional representation (letting smaller parties gain a foothold), blending the advantages of each.
Proportional representation's reliance on multimember districts is specifically what promotes multiparty systems: when multiple seats are available in a district, a party winning roughly 10% of the vote wins roughly 10% of the seats, so votes aren't "wasted" the way they are in single-member systems, and third, fourth, and fifth parties can win real representation rather than being squeezed out, which is why coalition governments become common. By contrast, first-past-the-post in single-member districts advantages large parties and effectively wastes votes cast for second-place finishers, pushing the system toward two-party dominance, as seen in both the UK (Conservative/Labour) and Nigeria (APC/PDP).
Electoral Manipulation
Authoritarian regimes tend to change electoral rules whenever it benefits the ruling party. Russia has changed its Duma electoral system several times: it was mixed (half districts, half PR) from 1993 to 2003, switched to fully proportional representation with a 7% threshold for the 2007 and 2011 elections (which shut out independents and regional candidates), and went back to the mixed system with a 5% threshold in 2016, after United Russia's share of the list vote had fallen and district races became the easier way for it to pile up seats. Each adjustment was calibrated to benefit United Russia and disadvantage the opposition. Democratic regimes, by contrast, tend to maintain stable rules over long periods: the UK has used first-past-the-post for every Commons seat since 1950, and Mexico's 300 district seats plus 200 PR seats have been the rule since 1988, with the 1990s reforms making elections fairer rather than favoring one party (even a 2026 proposal by the governing party to change how PR seats are filled failed). This kind of consistency helps enable genuinely fair competition over time.