Former President Donald Trump is leading Iowa by double-digits, but the race in the Hawkeye State has tightened over the last month, the latest National Research Inc. poll, commissioned by American Greatness, found.

According to the latest survey, Trump leads the pack in Iowa with 39 percent support among likely Iowa GOP caucus goers. DeSantis, who announced his presidential bid late last month, comes in 15 points behind with 24 percent support. That represents a tightening race, as Trump led by 18 points in last month’s survey — 44 percent to the governor’s 26 percent support.

However, the narrowing gap is not due to a boost in support for DeSantis, as DeSantis’s support actually decreased by two points over the last month, going from 26 percent support to 24 percent. Trump’s support decreased by five points, as he led with 44 percent support last month.

Rather, the biggest positive change in the survey came for Sen. Tim Scott, who saw a four point increase in the survey, jumping from one percent support last month to five percent this month. He now has more support than both former South Carolina Gov. Nikki Haley and former Vice President Mike Pence, who have four percent each.

Former New Jersey Gov. Chris Christie has two percent support among Iowa Republicans, followed by one percent who support anti-woke businessman Vivek Ramaswamy.

Further, the survey showed the number of undecided voters increasing, going from 15 percent to 21 percent — a six point increase.

According to American Greatness:

A fundamental issue for Governor DeSantis is that those voters who are favorable to him are splitting their vote between DeSantis and Trump. Among those who have a favorable opinion of both candidates, Trump holds a 16-point lead. Also, Trump holds an 8-point lead among voters who have been visited by the DeSantis campaign.

The survey also found Iowa Republicans continuing to view Trump as the best to improve the economy over DeSantis (+36), although that represents a six percent decrease from the 42 percent who said the same last month. They also view Trump as better suited to “oppose far-left progressives” (+18) and as someone who “cares about needs and concerns of people like me” (+15).

Trump also has a three-point edge among Republicans who believe Trump has the best chance of beating Biden. That is down from the six-point advantage he had last month as well.

The survey was taken June 5-7, 2023, among 500 likely Iowa Republican caucus goers. It has a +/- 4.38 percent margin of error.

The survey comes weeks after the release of the Emerson College Polling data showing Trump up in the Iowa caucus by 42 points.

“Wow! These are the real numbers in Iowa,” Trump said of the Emerson College poll on Truth Social. “Remember, I got the Farmers 28 Billion Dollars from China – Nobody else could have done that!”