Turkey's opposition faces an uphill battle in runoff with Erdogan

A hushed silence fell over the crowd outside the Istanbul headquarters of Turkish President Recep Tayyip Erdogan's ruling Justice and Development (AK) party.

Sullen faces turned to the election count on the large screen - Erdogan's vote had dropped below the 50% threshold needed to clinch the first round of Sunday's historic election.

The celebratory chants, which switched seamlessly between party and religious slogans, came to an abrupt halt, as did the drumbeat.

"We are not used to this. We're used to winning the first round," said 38-year-old Erdogan supporter Umran Ozdwmie. It was 1 a.m. in Istanbul and the street that the party faithful had poured into earlier in the evening was beginning to empty.

Suddenly, it throbbed back to life. Erdogan was to deliver an address from his balcony in the capital Ankara. Word was beginning to spread: the ruling party was bruised but not yet out of the game.

"Our moods might change, but Erdogan's rule won't," said 53-year-old Ismail Boyaci, 53. "We won't ever leave him."

Erdogan praised the election as a "feast of democracy."

"Our country has completed another feast of democracy with the 14th of May elections," said Erdogan. "Although the exact results are not clear yet, we are ahead."

A six-party coalition had coalesced to end Erdogan's 20-year rule, campaigning on a platform of change, restoring democratic institutions eroded by the strongman's tenure and jumpstarting the flailing economy. Such a united opposition front is unprecedented in Turkey.

Most Turkish polls had predicted a knife-edge lead for the main opposition candidate Kemal Kilicdaroglu. In the end, the reverse happened. Erdogan secured a five-point lead over his principal opponent, destining them to a run-off vote.

The third candidate - the far-right politician Sinan Ogan - was left with a potentially decisive 5% of the vote.

The new kingmaker has conditioned his endorsement of either candidate on hardened policies towards refugees and some Kurdish groups he perceives as terrorists.

"When we have a decision (on endorsement) of course we are going to offer it to both sides," Ogan told CNN's Becky Anderson on Monday. "It could be Erdogan. It could be Kilicdaroglu. We don't have a clear decision at the moment."

"What we're thinking is all the political parties should exclude terror organizations," he said. "We don't have to give our support to either of the parties; there is no such rule."

But analysts predict that Ogan's ultranationalist followers will be more likely to vote for Erdogan in the next round. Erdogan's ruling party has also emerged from Sunday's election with the largest parliamentary bloc.

This leaves the opposition facing an uphill struggle to win the runoff. Kilicdaroglu struck a defiant tone on Monday. "I swear I will fight until the end. I. Am. Here," he said in a video released on social media.

Among other things, the election results exposed the opposition's limited ability to seize on the disgruntlement of a populace reeling from an economic crisis and, in the southeast, a devastating earthquake.

Opposition voters who CNN spoke to before polls closed had seemed upbeat. They said they were voting for "justice and freedom," for a revitalized economy and for checks and balances.

Erdogan supporters drew a sharp contrast. Times of crisis require a strongman to forge a path to recovery, they said. Erdogan endows a muscular stature on the country, and, importantly for many voters, he was religious.

Voter turnout was very high, at nearly 90%. CNN saw several ill people being carried into the polling stations, including one person who was brought in on a stretcher, attached to an oxygen machine. It was a battle for the soul of the nation, and Turks from all walks of life were determined to participate.

Yet even as voters called for change, there are loyalties here that seem immutable.

When CNN reported from Erodgan strongholds in the country's earthquake zone last week, we found that support for the president remained robust. This was confirmed in the election results which showed that support for the leader remained alive and well, despite an shambolic initial response.

"People make mistakes and you've got to love people despite their mistakes," said Nuray Canpolat from outside her tent in Erdogan stronghold Kahramanmaras, the epicenter of the quake.

"First, God saves us. Then our President Erdogan saves us."

Ahead of the run-off vote, Erdogan now has two weeks in which to save himself - and all the indications are that he begins, as ever, from a place of strength.

CNN's Jomana Karadhsheh and Gul Tuysuz contributed to this report from Turkey.