Rodrigo Duterte Is Expected to Again Become Mayor of Davao City

Six weeks ago, a van piled high with flowers pulled up at the International Criminal Court’s detention center in The Hague. The court also received deliveries of birthday cards. Lots and lots of them.

They were all for the newest inmate, Rodrigo Duterte, the former president of the Philippines, who turned 80 on March 28. He is accused of crimes against humanity, and he could spend the rest of his life in prison.

“The place was inundated with flowers, and I brought some of the mail out because they didn’t know what to do with it,” Nicholas Kaufman, Mr. Duterte’s lawyer, said in a telephone interview. He said he had left with three sacks of mail for Mr. Duterte that the court was unable to vet. In the Philippines, thousands of people dressed in the green associated with Mr. Duterte’s political party flooded the streets of Davao City.

Mr. Duterte, who ordered a brutal antidrug campaign in which tens of thousands of people died during his presidency, remains very popular in the Philippines. With Filipinos voting in midterm elections on Monday, he is expected to win another term as mayor of Davao City, his eighth, by a landslide. For now, he remains eligible for office.

Mr. Duterte’s sudden arrest and extradition to The Hague in March has sharply divided the Philippines. While some polls show that a majority of Filipinos back the international investigation, many of Mr. Duterte’s supporters believe that he is a victim of political persecution by President Ferdinand Marcos Jr., once an ally of the Duterte clan.

Soon after Mr. Duterte’s dramatic arrest, Mr. Marcos’s approval rating plummeted to 25 percent from 42 percent a month earlier, in a survey conducted by Pulse Asia. But that of Sara Duterte — the current vice president and daughter of Mr. Duterte — rose to 59 percent from 52 percent.