ORLANDO, Fla. -- As the clock counts down to the primary election on Aug. 28, the Republican primary for the governor’s seat continues to heat up.

Rep. Ron DeSantis holds slim lead over Ag Comm. Adam Putnam

16 percent of Republican likely voters are undecided

DeSantis does better among conservatives

Putnam does better among young Republicans

DECISION 2018 VOTING GUIDE: Candidates, county-by-county resources, FAQs, more

RELATED: Poll: Graham, Levine tied among Democratic candidates for governor

Our exclusive Decision 2018 Gubernatorial Poll shows Rep. Ron DeSantis with a slim lead over Agriculture Commissioner Adam Putnam, with a difference of only 2 percent.

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DeSantis is getting 40 percent approval and Putnam is getting 38 percent. Sixteen percent of the likely Republican voters we interviewed are undecided, while the rest of the field barely made it on the board.

With President Donald Trump endorsing DeSantis, many thought he would run away with the race, but that might no longer be the case.

“So it seemed as if he had all the momentum, and this race was all over but the shouting, as they say. But it appears that it actually is much closer,” said Dr. Aubrey Jewett, UCF Political Science professor.

One area where DeSantis is pulling ahead of Putnam is with conservative republican voters.

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“The problem for Putnam here is that within the Republican electorate there are a lot more conservatives than there are moderates. So that is probably why DeSantis is ahead at this point,” said Jewett.

But in Putnam’s favor, he is fairing better with young Republicans ages 18 to 34. He received 54 percent favorability over DeSantis’ 22 percent.

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“It could be because of the Donald Trump factor. It seems that older voters were more likely to support Donald Trump, particularly Republican voters. And whereas younger Republican voters were a little more skeptical,” said Jewett.

Either way, the race at this point is far too close to even make a guess who could win. Jewett adds that if it stays that close, that a big deciding factor could be the 16 percent of undecided voters.

“There still is some percentage of Republican voters that haven’t made up their minds yet. And this poll definitely suggests that they could be the decisive factor. The undecided vote right now at 10, 15, 20 percent,” said Jewett.

Our exclusive Decision 2018 poll interviewed 558 likely Republican primary voters over the last three days. The Credibility Interval was +/- 5.2 percentage points.

Decision 2018 Poll Demographics

Here is a deeper look at demographics and the background of likely Republican voters for the Aug. 28 primary, according to our Exclusive Decision 2018 Gubernatorial Poll.