Editing Elections in Chile (section)

=== Electoral system prior to 2017 ===
Until 2017, Chile's electoral system featured 60 districts for the Chamber of Deputies and 19 senatorial constituencies, each electing exactly two representatives,<ref name="electorallaw" /> totaling 120 deputies and 38 senators. Chile was unique in applying the D'Hondt method nationwide to uniformly two-seat divisions.<ref name="cieplan">{{cite web |author=Carey, John M |year=2009 |title=Ingeniería electoral: ¿qué nos muestran las investigaciones académicas sobre los efectos anticipados de las reformas electorales? |trans-title=Electoral engineering: What does academic research show us about the anticipated effects of electoral reforms? |url=http://www.cieplan.org/biblioteca/detalle.tpl?id=184 |access-date=2011-12-25 |work=Fortalecimiento de la Democracia: Reforma del Sistema Electoral Chileno / Chapter 8 |page=234 |language=es}}</ref><ref>{{cite web |author=Altman, David |year=2004 |title=Redibujando el Mapa Electoral Chileno: Incidencia de Factores Socioeconómicos y Género en las Urnas |url=http://www.icp.uc.cl/daltman/index_archivos/Altman-2004-Revista%20de%20Ciencia%20Pol%C3%ADtica%2024%20(2)%2049-66.pdf |url-status=dead |archive-url=https://web.archive.org/web/20110707012224/http://www.icp.uc.cl/daltman/index_archivos/Altman-2004-Revista%20de%20Ciencia%20Pol%C3%ADtica%2024%20(2)%2049-66.pdf |archive-date=2011-07-07 |access-date=2010-12-22 |work=Revista de Ciencia Política / Vol. XXIV / Nº 2 |publisher=Instituto de Ciencia Política, [[Pontificia Universidad Católica de Chile]]}}</ref><ref name="flacso">{{cite book |author=Fuentes S., Claudio and Marcela Ríos T. |url=http://www.flacso.cl/publicaciones_ficha.php?publicacion_id=354 |title=Una reforma necesaria: Efectos del sistema binominal |date=January 2007 |work=[[Latin American Social Sciences Institute|FLACSO Chile]] |isbn=978-956-205-215-3 |edition=2nd |location=Santiago |pages=17, 32 |language=es |trans-title=A Necessary Reform: Effects of the Binomial System |access-date=2011-10-23 |archive-url=https://web.archive.org/web/20120423115927/http://www.flacso.cl/publicaciones_ficha.php?publicacion_id=354 |archive-date=2012-04-23 |url-status=dead}}</ref> In each electoral district or constituency, the two entities with the most votes—whether pacts, parties, or independent candidates—each won one seat. To claim both seats, the leading entity needed at least twice as many votes as the runner-up.<ref name="electorallaw" />

A 2015 reform law reorganized electoral divisions, reducing the number of districts and aligning senatorial constituencies with regional boundaries. This new system was implemented in the 2017 general elections<ref>{{cite web |date=5 May 2015 |title=LEY-20840 05-MAY-2015 MINISTERIO DEL INTERIOR Y SEGURIDAD PÚBLICA - Ley Chile - Biblioteca del Congreso Nacional |url=http://www.leychile.cl/Navegar?idNorma=1077039 |website=leychile.cl}}</ref> and significantly altered Congress's composition.<ref>{{Cite news |last=Sajuria |first=Javier |title=Analysis {{!}} Chile just went to the polls — and transformed its legislature |url=https://www.washingtonpost.com/news/monkey-cage/wp/2017/11/21/chile-just-went-to-the-polls-and-transformed-its-legislature/ |access-date=2020-07-11 |newspaper=Washington Post |language=en}}</ref>

====Criticism====
{{see also|Gerrymandering#Chile}}

The [[binomial voting system]] was introduced by the military dictatorship that governed Chile until 1990. It replaced the [[proportional representation]] system used until 1973 and limited each electoral division to two seats. District boundaries were drawn to favor right-leaning parties, often benefiting rural areas with greater support for the [[Augusto Pinochet|Pinochet]] regime. Vote-to-seat disparities were especially pronounced in districts where the regime had received lower support in the [[1988 Chilean national plebiscite|1988 plebiscite]].<ref>{{cite web |author=Valenzuela, Arturo and Peter Siavelis |year=1991 |title=Ley electoral y estabilidad democrática: Un ejercicio de simulación para el caso de Chile |url=http://www.cepchile.cl/dms/archivo_1320_1445/rev43_valenzuela.pdf |url-status=dead |archive-url=https://web.archive.org/web/20120119182939/http://www.cepchile.cl/dms/archivo_1320_1445/rev43_valenzuela.pdf |archive-date=2012-01-19 |access-date=2011-12-29 |work=Estudios Públicos Nº 43 |publisher=[[Centro de Estudios Públicos]] |page=39 |language=es |location=Santiago}}</ref>

Changing the system was made difficult by constitutional provisions requiring a three-fifths majority in both houses of Congress.<ref name="constitution" /> Critics, particularly from the [[Concert of Parties for Democracy]], argued that the system distorted representation by undercutting majorities and amplifying right-wing presence.<ref>{{cite web |author=Carey, John M. |year=2006 |title=Las virtudes del sistema binominal |trans-title=The Virtues of the Binomial System |url=http://www.scielo.cl/scielo.php?pid=S0718-090X2006000100016&script=sci_arttext |access-date=2011-11-26 |work=Revista de Ciencia Política / Vol. 26 / Nº 1 |pages=226–235 |language=es |issn=0718-090X |location=Santiago}}</ref> Supporters on the right defended the system as a stabilizing force<ref>{{cite web |title=Coloma defiende el sistema binominal: "Ha dado estabilidad a Chile" |url=http://www.emol.com/noticias/nacional/2011/10/26/509991/coloma-defiende-el-sistema-binominal-ha-dado-estabilidad-a-chile.html |access-date=2011-10-27 |publisher=Emol.com}}</ref><ref name="sciencespo">{{cite web |year=2009 |title=Chili : Système électoral |url=http://www.opalc.org/web/index.php?option=com_content&view=article&id=328:chili--systeme-electoral&catid=131:systemes-electoraux-et-legislations&Itemid=208 |url-status=usurped |archive-url=https://archive.today/20130415145106/http://www.opalc.org/web/index.php?option=com_content&view=article&id=328:chili--systeme-electoral&catid=131:systemes-electoraux-et-legislations&Itemid=208 |archive-date=April 15, 2013 |access-date=2011-11-26 |work=Observatoire Politique de l'Amérique latine et des Caraïbes de [[Sciences Po]] - Opalc.}}</ref> that encouraged broad coalitions.<ref>{{cite web |author=Siavelis, Peter |year=2004 |title=Sistema electoral, desintegración de coaliciones y democracia en Chile: ¿El fin de la Concertación? |url=http://www.scielo.cl/scielo.php?pid=S0718-090X2004000100003&script=sci_arttext |access-date=2011-11-26 |work=Revista de Ciencia Política / Vol. XXIV / N° 1 |pages=58–80 |language=es |issn=0718-090X |location=Santiago}}</ref> The left criticized it as undemocratic,<ref name="sciencespo" /> excluding parties and candidates outside the two main blocs.<ref name="cieplan" />