FORMER President Gloria Macapagal Arroyo has endorsed former Senator Ferdinand “Bongbong” R. Marcos, Jr. for president, saying she expects a landslide victory for the only son of the late dictator Ferdinand E. Marcos.

“I know all of us are for Bongbong Marcos,” the ex-president, who is running for Pampanga representative, said at her 75th birthday event in Pampanga province on April 4, according to an e-mailed statement from her office on Tuesday.

“I hope you give Sara the equal support you gave Noli de Castro, who was my vice-president,” she added, referring to Mr. Marcos’ running mate Davao City Mayor and presidential daughter Sara Duterte-Carpio.

Ms. Carpio attended the event, according to the statement.

Pampanga, a province northwest of the capital Manila, is one of the largest vote-rich provinces in the country. It has more than 1.5 million registered voters this year.

“We are also endorsing her because of the help which her father, President Rody Duterte, provided Pampanga,” Ms. Arroyo said of Ms. Carpio. “Let us return the favor.”

Ms. Arroyo’s father, the late President Diosdado P. Macapagal, Sr. and the late dictator were bitter rivals in the Liberal Party, the political group of opposition presidential bet Vice-President Maria Leonor “Leni” G. Robredo.

The elder Mr. Marcos left the Liberal Party and joined the Nacionalista Party to run against Mr. Macapagal for president in 1965.

Mr. Macapagal and his daughter helped the anti-dictatorship movement, which later opposed Ms. Arroyo’s rule after alleged cheating in the 2004 presidential election.

The government under her predecessor Benigno S.C. Aquino III indicted her for election sabotage, for which she was arrested in Nov. 2011 while confined at the St. Luke’s Medical Center in Taguig City.

She was transferred to the Veterans Memorial Medical Center in Quezon City a month later and was released from hospital arrest on bail in July 2012.

Three months later, she refused to enter a plea on charges she misused $8.8 million in state lottery funds while she was president, for which she got arrested again and placed on hospital arrest

In July 2016, the Supreme Court dismissed the corruption charges against her and ordered her release from the hospital where she had been detained since 2012.

Meanwhile, government prosecutors have endorsed the indictment of a delivery rider for cyber-crime after he allegedly threatened on Twitter to shoot and kill Mr. Marcos. They recommended a P72,000 bail.

In a statement dated April 4 and released on Tuesday, the Office of the Prosecutor General said the man, who was being detained, would be charged with grave threats in relation to the Cyber-crime Act. The case will be filed at a Quezon City trial court.

“I am not afraid to go to jail and I am not afraid to die,” the delivery rider tweeted in Filipino, according to the Justice department. “It is a great honor to avenge my fellow activists who were abused during martial law.”

Quezon City police arrested the man last week. Mr. Marcos’s camp filed the complaint.

“Grave Threat is a crime against public security,” said the Justice department, which ordered the National Bureau of Investigation (NBI) in January to validate an anonymous tip from a TikTok user who allegedly posted an assassination plot against the late dictator’s son.

The man who owned the TikTok account denied the allegations and said his identity had been illegally used to make the suspicious post.

Justice Secretary Menardo I. Guevarra said in January the NBI would prioritize any validated information on threats to the security of any presidential candidates. — Kyle Aristophere T. Atienza and John Victor D. Ordoñez