(CNN) It's an election that could change Indonesia.

Voters in the capital of Jakarta went to the polls Wednesday to elect a new governor.

But more is at stake than who governs the sprawling, chaotic metropolis of 30 million people.

The contest between the incumbent, Basuki Tjahaja Purnama, an ethnic Chinese Christian commonly known as Ahok, and his two Muslim opponents has raised questions over whether Indonesia, the world's most populous Muslim nation, will remain a moderate Muslim society.

It could even determine who will be the next president of Indonesia after the 2019 national election.

Preliminary exit polls and surveys have Ahok and former Education and Culture Minister Anies Baswedan as the top two candidates, with neither breaking the 50% threshold to prevent a runoff.

Jakarta governor Basuki Tjahaja Purnama, known as Ahok, after casting his vote at a polling station on Wednesday February 15.

A result won't be known for two weeks, and if no one wins a majority, a second round of voting will take place April 19.

"If (incumbent) Ahok (were) to lose, other than politicians using religion as a tool, Islamists will use it to change Islam into Indonesia to their own meaning, that isn't Indonesian," Tobias Basuki, a researcher at the Indonesian think tank the Center for Strategic and International Studies , told CNN.

"They will gain an upper hand. (This) will be the first litmus test."

Polling data before Wednesday's election showed Ahok and Baswedan were expected to face off in the second round in April.

Indonesians rally in support of Muslim clerics at the National Monument in Jakarta this month.

Rise of conservatism

More than 200 million Muslims -- 87% of the population -- call Indonesia home.

It's generally a moderate country known for a tolerance for other religions and ways of life with the exception of the conservative Aceh province.

"Indonesia's political Islam is very different from the Middle East -- for example, non-Muslim leaders of a Muslim majority is normal; intermarriage is accepted," researcher Basuki said.

However, experts say Indonesia is becoming increasingly conservative, with large anti-LGBT protests in Jakarta and passionate reactions to allegations of blasphemy commonplace in recent years.

Photos: Jakarta Protests Muslim protesters marched on Jakarta's governor's office on Friday, November 4. Tens of thousands of Muslims descended upon the Indonesian capital demanding Jakarta governor Basuki Tjahaja Purnama -- commonly known as Ahok -- be prosecuted on accusations that he committed blasphemy. Hide Caption 1 of 8 Photos: Jakarta Protests An estimated 200,000 people converged on the center of the Indonesian capital to demand the arrest of its minority-Christian governor on November 4. Hide Caption 2 of 8 Photos: Jakarta Protests Muslim leaders broadcast their message as they march past Jakarta's governor's office on November 4. Hide Caption 3 of 8 Photos: Jakarta Protests Indonesian riot police were on standby in the compound of the governor's office on November 4. Hide Caption 4 of 8 Photos: Jakarta Protests Protesters sat atop a speaker system during the demonstration on November 4. Hide Caption 5 of 8 Photos: Jakarta Protests Indonesian policewomen stood guard during the protest outside Jakarta's City Hall on November 4. Hide Caption 6 of 8 Photos: Jakarta Protests Female Muslim protesters marched outside the governor's office on November 4. Hide Caption 7 of 8 Photos: Jakarta Protests The march continued toward the presidential palace on November 4. Hide Caption 8 of 8

Ahok is from two prominent minorities -- he's a Christian and of Chinese ethnicity. Both have been made an issue in the governor's campaign, said Greg Fealy, an associate professor in Australian National University's Coral Bell School of Asia Pacific Affairs.

He is also on trial over allegations of blasphemy after an edited video of his comments about the Quran triggered large demonstrations.

"It's fairly clear that he was charged with blasphemy for political reasons , because they had to acquiesce to what the mob wanted -- that is a bad thing for Indonesia," Fealy told CNN.

If Ahok loses the election, Fealy said, Indonesian political parties may be less likely to field candidates from ethnic and religious minorities.

"If there was a major position, like governor of East Java, for a minority, this is too big a risk," he said.

Indonesian Muslims take part in an anti-Ahok rally in Jakarta ahead of this week's election.

Challenge to Indonesia's President

The fierce campaign to topple Ahok has another target in its sights -- Indonesian President Joko Widodo, also known as Jokowi.

used his position as governor of Jakarta to In 2014, Jokoused his position as governor of Jakarta to catapult himself into national politics , winning the presidency after two years as governor.

"Before (Joko) the governorship was very boring. ... This is the first time Jakarta's seat is considered a steppingstone to the presidency," Basuki told CNN.

Ahok is a longtime ally of the Indonesian leader's, becoming his running mate in the 2012 Jakarta election and assuming the governorship after Joko stepped down.

Indonesian President Joko Widodo, right, congratulates the Jakarta governor at his swearing-in in 2014.

Former Indonesian Lt. Gen. Prabowo Subianto was Joko's primary opponent in the 2014 election and is expected to run again in 2019.

Whoever wins the Jakarta governorship would have a high-profile platform from which to challenge Joko in 2019 -- or be an invaluable ally to whoever does run.

"Jokowi very much wants Ahok to win, and he's been trying to back him as much as he could. ... He most certainly doesn't want Prabowo's guy to be governor (Baswedan). He could be quite a threat to Jokowi," Fealy said.

Basuki added, "If Jakarta's governor is from the so-called opposition, they will impede (Joko's) every step, not just in the 2019 election but beyond that."

Joko, right, backs Jakarta's incumbent over ex-Education and Culture Minister Anies Baswedan.

Jakarta's brash governor

A second round of voting is expected to be tough.

"I think that will be the really ugly one. What we've seen so far hasn't been pretty, but I think there'll be people playing for very high stakes," Fealy said.

"I think it will be much more virulently sectarian and racist."

Election officials count ballots in the elections for Jakarta governor on Wednesday February 15.

Ahok's supporters say he is the only choice to lead Jakarta for the next five years.

"I'm very sure those in the grass roots will choose him," Jakarta resident Nyoman Kamajaya told CNN. "Why? Because they're not choosing an imam. They're choosing a leader."

But a large number of people still do not support the Christian Chinese governor, with some saying their religion must be "defended."

"I am Muslim and I will only accept Muslims as my leaders," Jakarta Islamic Center volunteer Suci told CNN.

Dancers perform for supporters of the Jakarta governor at his final campaign rally Saturday.

Whatever the result, Ahok will have to bear some of the blame for his brash, confrontational style of governing, Fealy said.

"He's a very combative, outspoken, reckless kind of character who has achieved a lot for Jakarta, but he's a character who has created a lot of antipathy toward him," he said.