Editing Gerrymandering (section)

===Chile===

The [[Military dictatorship of Chile (1973–1990)|military government]] which ruled [[Chile]] from 1973 to 1990 was ousted in a [[1988 Chilean national plebiscite|national plebiscite]] in October 1988. Opponents of General [[Augusto Pinochet]] voted NO to remove him from power and to trigger democratic elections, while supporters (mostly from the right-wing) voted YES to keep him in office for another eight years.

Five months prior to the plebiscite, the regime published a law regulating future elections and referendums, but the configuration of electoral districts and the manner in which [[National Congress of Chile|National Congress]] seats would be awarded were only added to the law seven months after the referendum.<ref>{{cite web|url=http://www.leychile.cl/Navegar?idNorma=30082&tipoVersion=0 |title=Ley-18700 06-May-1988 Ministerio del Interior |publisher=Leychile.cl |access-date=19 December 2010}}</ref><ref>{{cite web|url=http://www.leychile.cl/Navegar?idLey=18799 |title=Ley-18799 26-May-1989 Ministerio del Interior |publisher=Leychile.cl |access-date=19 December 2010}}</ref>

For the [[Chamber of Deputies of Chile|Chamber of Deputies]] (lower house), [[Electoral division of Chile|60 districts]] were drawn by grouping (mostly) neighboring [[Communes of Chile|communes]] (the smallest administrative subdivision in the country) within the same [[Regions of Chile|region]] (the largest). It was established that two deputies would be elected per district, with the most voted coalition needing to outpoll its closest rival by a margin of more than 2-to-1 to take both seats. The results of the 1988 plebiscite show that neither the "NO" side nor the "YES" side outpolled the other by said margin in any of the newly established districts. They also showed that the vote/seat ratio was lower in districts which supported the "YES" side and higher in those where the "NO" was strongest.<ref>[http://flacsochile.org/biblioteca/pub/memoria/1989/000261.pdf Documento de trabajo. Programa FLACSO-Chile. Número 428, septiembre 1989] {{Webarchive|url=https://web.archive.org/web/20171109022850/http://flacsochile.org/biblioteca/pub/memoria/1989/000261.pdf |date=9 November 2017 }}. FLACSO Chile Biblioteca.</ref><ref>{{cite journal |last1=Navia |first1=Patricio |last2=Rojas |first2=Priscilla |title=Representación y tamaño de los distritos electorales en Chile, 1988–2002 |trans-title=Representation and size of electoral districts in Chile, 1988–2002 |language=es |journal=Revista de ciencia política (Santiago) |date=2005 |volume=25 |issue=2 |pages=91–116 |doi=10.4067/S0718-090X2005000200004 |doi-access=free }}</ref> In spite of this, at the [[1989 Chilean general election|1989 parliamentary election]], the center-left opposition was able to capture both seats (the so-called ''doblaje'') in twelve out of 60 districts, winning control of 60% of the Chamber.

[[Senate of Chile|Senate]] constituencies were created by grouping all lower-chamber districts in a region, or by dividing a region into two constituencies of contiguous lower-chamber districts. The 1980 Constitution allocated a number of seats to appointed senators, making it harder for one side to change the Constitution by itself. The opposition won 22 senate seats in the 1989 election, taking both seats in three out of 19 constituencies, controlling 58% of the elected Senate, but only 47% of the full Senate. The unelected senators were eliminated in the 2005 constitutional reforms, but the electoral map has remained largely untouched (two new regions were created in 2007, one of which altered the composition of two senatorial constituencies; the first election to be affected by this minor change took place in 2013).