This post was updated at 11:00 p.m., Aug. 28, 2018.

Democratic candidate for governor and billionaire businessman Jeff Greene threw his support behind Tallahassee Mayor Andrew Gillum Tuesday, after Gillum secured the party's nomination for governor with over 34 percent of the vote.

"Nobody expected this," Greene said after the race was called. "[Gillum] was able to mobilize his base, he's a smart...very inspiring guy."

Greene, a real estate developer, had campaigned heavily on spending more money on public education and on environmental issues. He specifically endorsed two years of free universal Pre-K.

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Early Tuesday Greene said he felt confident his strategy would bring more voters to the polls. He spent more than $34.5 million of his own money on his campaign.

“I think that with our ground game, which has been very robust all over the state of Florida, I think we’re pulling votes out that people will be surprised to see,” he said.

But he later admitted he lost confidence last week.

"I basically stopped spending money a week ago," Greene told WLRN over the phone. "I knew...I saw where the polls were."

Multiple polls anticipated Greene would not be able to beat out Gwen Graham, who led the polls in the days before the race.

Greene also canceled his public watch party in Palm Beach late in the day before the election. Instead, he opted for a private party at home.

“I’m a home person truthfully, and we were going to do it at our hotel, we own the hotel we were doing it - the Tideline - but we just want to have a more intimate place so we can sit in the living room, watch TV, be in our jeans and comfortable…and hopefully have an amazing celebration.”

Greene partly blamed negative ads that candidate Philip Levine ran against him, including one that alleged Greene is close to President Donald Trump.

"I made a mistake of not responding in a more progressive way," he said.

Greene said after he voted Tuesday morning in Palm Beach that he would endorse the winner if he lost. True to his word, Greene's campaign released a statement Tuesday night which read in part:

“I wish Andrew and all Democrats luck as our party works together to defeat Republicans at the polls in November. Let’s make history, and make Andrew Gillum the next Governor of Florida."