Venezuela is formally a multi-party constitutional republic, but in recent years, political power has been concentrated in a single party with an increasingly authoritarian executive exercising significant control over the legislative, judicial, human rights ombudsman, and electoral branches of government. On April 14, authorities announced that Nicolas Maduro had won the presidency by a 1.49 percent margin, amid allegations of pre- and post-election fraud based on a number of irregularities, including government interference, the use of state resources by the ruling party, and voter manipulation. The electoral and judicial bodies rejected the opposition's claims and refused to conduct a full audit of the electoral process. The Union of South American Nations electoral "accompaniment" delegation urged all parties to respect the election results while publicly supporting an audit of the results. Some domestic election observation groups, nongovernmental organizations (NGOs), and the Institute for Advanced European Studies (IAEE) questioned the constitutional legitimacy of Nicolas Maduro's election. Authorities maintained effective control over security forces. Security forces committed human rights abuses. The principal human rights abuses reported during the year included corruption, politicization of the judicial system, and government actions to impede freedom of expression and restrict freedom of the press. The government did not respect judicial independence or permit judges to act according to the law without fear of retaliation. The government used the judiciary to intimidate and selectively prosecute political, union, business, and civil society leaders who were critical of government policies or actions. The government harassed and intimidated privately owned television stations, other media outlets, and journalists throughout the year, using threats, fines, property seizures, targeted regulations, arrests, and criminal investigations and prosecutions.