SOFIA, Bulgaria—Exit polls in Bulgaria suggest that incumbent Rumen Radev is the apparent winner in the country’s presidential runoff. Partial official results are expected later Sunday. Surveys by several polling organizations give Radev, 58, about 65 percent of the vote. He is seeking a second five-year term in the largely ceremonial post. Sofia University rector, Atanas Gerdzhikov, 58, who was backed by the center-right GERB party of former Prime Minister Boyko Borissov, is said to be trailing with 32 percent support. Some 3 percent voted against both candidates. Radev, a vocal critic of Borissov and firm supporter of last year’s anti-corruption protests, has attracted many Bulgarians who are fed up with politicians they see as corrupt. Radev has appointed two consecutive caretaker governments that unveiled alleged corruption in Bulgaria’s industrial and financial sectors. “Let’s not give the past a chance to torpedo our future. Let everyone find 15 minutes today …