JAKARTA -- As Indonesia heads toward a presidential election on April 17, both ruling and opposition parties are increasingly focusing on conservative Muslims, a voter bloc that could decide the contest between incumbent Joko Widodo and his more religious opponent.

Indonesia's Muslim majority is generally considered moderate and tolerant of other religions. But a more firebrand attitude is on the rise, particularly in less urban areas and when it comes to top leadership posts like the presidency. The election of a Christian governor in Jakarta in 2014 has only hardened certain segments of the population.

Fifty-nine percent of respondents to a 2018 poll by the Indonesia Survey Institute said they would object to a non-Muslim president. That is up significantly from 48% in 2016. Assuming this represents the country as a whole, over 100 million voters now feel this way.

Although Widodo is Muslim, many consider the former businessman to be relatively secular. In fact, this perception ended up dragging him down toward the end of the last race in 2014. In order to boost his support among conservatives this time around, he has chosen 76-year-old senior cleric Ma'ruf Amin as his vice presidential running mate.

Amin leads the Indonesian Ulema Council, the country's top Muslim clerical body. He has actively toured Islamic schools and other facilities mainly on the island of Java, helping the ticket secure a 20-point lead over the opposition.

"I am a nationalist. He is a devout religious figure. We complement each other well," Widodo said back in August when announcing his candidacy.

Widodo is running against former Lt. Gen. Prabowo Subianto, the same man he faced back in 2014. The leader of the opposition Great Indonesia Movement Party, or Gerindra, was an instrumental supporter of the Muslim candidate who challenged -- and beat -- Jakarta's incumbent Christian governor in 2017. Subianto's running mate is Sandiaga Uno, who stepped down as Jakarta's deputy governor to join the ticket.

Uno took aim at the current administration in a televised debate on Sunday. "Foreigners are gaining jobs but our own citizens cannot," he said.

Amin responded that foreign workers should only be allowed to take jobs that Indonesians cannot. Widodo's running mate also said the country should encourage technology transfers, indicating the country's shift toward more conservative forms of Islam could make it harder for foreign companies to operate here.