From Wikipedia: this picture shows very roughly how gerrymandering can influence electoral results in non-proportional or semi-proportional systems as in Venezuela now.
Next year we have National Assembly elections in Venezuela. They are very important: the opposition had unwisely pulled out of the 2005 elections when it declared conditions were not fair. Now the government has almost all the seats in the Asamblea but for a small group of dissidents. The National Assembly president and the pro-government mob prevents them in the most shameful way to discuss their ideas or defend non-governmental positions.
The president already declared his party must get 75% of the seats at the Assembly to guarantee his revolution. If not, he said, violence would take place. Some months ago the current National Assembly approved a new electoral law that allows massive gerrymandering: The Electoral commission will be able to modify electoral districts at will at any moment. On top of that the proportional representation will be violated (see below in the update).
The government recently published the public call for Venezuelans to put forward their candidates that, in their turn, will select the new heads of the National Electoral Commission. The government made the call in two very obscure newspapers that no one reads: Vea and La calle. Both are pro-government. The first one has theoretically a circulation of 60000. It is mostly financed by government propaganda. The second one did not even have a web page as of today (15.10.09). In any case: nobody from the opposition found out about the call and only members of the governmental party came up. People were expecting the call in Últimas Noticias (also rather pro-government) and other newspapers and through some call on pro-government TV or normal pro-government sites.
One of the few dissident voices at the National Assembly declared to Tal cual that all the electors are from the Partido Socialista Unificado de Venezuela.
Jorge Rodríguez, previous head of the Electoral commission:
Jorge Rodríguez later became Vice-president when he finished his job at the Electoral commission and now he is Mayor of the Libertador Municipality. Here he is next to notorious Lina Ron.
The current head of the Electoral commission is Tibisay Lucena. I wonder if she is going to take some vacation for a short time before she graciously accepts the government's reward for her work at the Electoral commission.
PS. Here you can see one of the chavista deputies talking while drunk at the National Assembly.
UPDATE: I got a new update from NGO Ojo Electoral. It describes how the new electoral law is going to destroy any sense of proportionality. PLEASE, LOOK AT THIS!