The REAL question is:
HOW IN THE WORLD DID A CHRISTIAN GOVERNOR GET ELECTED IN A MUSLIM COUNTRY?
Probably perceived as a compliant dhimmi. Many Ba’athists in Syria and Iraq are and were nominal Christians.
There are regions and towns that are majority Christian, even in Indonesia and Iraq. People tend to group / clump in communities of the same ethnicity / religion.
Actually, he did not. He was a businessman who owned a tin smelter in Bangka, and got in as the Deputy Governor on the ticket with Jokowi, who was immensely popular. When Jokowi became President, Ahok became the governor, and the headbangers have been in a twist ever since.
Ahok is, perhaps after Ali Sadikin, the best governor Jakarta has ever had. He gets things done, as the Chinese usually do, and he has instilled some discipline in the slothful government employees. Many of the most serious problems, like flooding and traffic gridlock, are being addressed and remedied. The powers that be cannot stand him because he is confrontational and speaks the truth to people who have no familiarity with such a concept.
If Ahok loses the election in February, Jakarta goes down the tubes.