Members of Bukele's New Ideas Party in the Legislative Assembly voted through the reform on Thursday, 18 months after Bukele won a second term in a landslide victory, despite a constitutional prohibition on consecutive terms. The Supreme Court, packed with pro-Bukele justices, waived the ban on grounds that it infringed Bukele's human rights.
Opposition politicians and human rights organizations condemned the move, saying it removed one of the last remaining checks on power and brought the country a step closer to becoming a one-party state.
"Today, democracy has died in El Salvador," said opposition Republican National Alliance MP Marcela Villatoro.
Human Rights Watch said it was a power grab by Bukele aimed at ushering in a dictatorship.
"He's very clearly following the path of leaders who use their popularity to concentrate power to undermine the rule of law and eventually to establish a dictatorship," said HRW Americas deputy director Juan Pappier.
Cristosal, El Salvador's leading human rights organization, which fled the country for Guatemala two weeks ago citing threats and intimidation against its staff, criticized the lack of process and the way the change was rushed through.
"The day before vacation, without debate, without informing the public, in a single legislative vote, they changed the political system to allow the president to perpetuate himself in power indefinitely and we continue to follow the well-travelled path of autocrats," said Cristosal executive Noah Bullock.
Bukele's popularity mainly stems from a crime crackdown, targeting gangs in particular, that has seen El Salvador transformed from one of the most violent nations in the world to one of the safest in the region.
However, he is a divisive figure among Salvadorans.
His policies, including the use of emergency powers to detain as many as 75,000 people without due process, have drawn fire from human rights groups such as Amnesty International, which has said El Salvador was engaged in a "gradual replacement of gang violence with state violence."
The United States got pulled into questions around El Salvador after Maryland resident Kilmar Abrego Garcia, an undocumented Salvadoran migrant, was detained in one of Bukele's notorious 'mega prisons' after being wrongly deported to El Salvador in violation of a 2019 court order that said he could not be deported there.
He was among a group of 261 inmates imprisoned in one of the huge penal facilities after being deported by the Trump administration, who it said were either members of the Venezuelan Tren de Aragua gang or the Salvadoran-dominated MS-13.
Abrego Garcia, who was accused of being a member of the MS-13, was returned to the United States in June at the request of the Justice Department to face federal migrant smuggling charges in Tennessee.
