SALT LAKE CITY — Lt. Gov. Spencer Cox has pulled ahead of former Gov. Jon Huntsman Jr. in the latest Deseret News/Hinckley Institute of Politics poll as Republican voters will cast ballots this month in the race for Utah governor.

In new results released Monday, Cox is at 30% and Huntsman 23% among respondents who say they definitely would vote in the June 30 GOP primary election.

Former Utah House Speaker Greg Hughes has surged to 19%, while former Utah Republican Party Chairman Thomas Wright continues to lag behind at 4%, according to the poll.

About a quarter of those surveyed said they weren’t sure who they would choose to be the GOP nominee, though that will change as Utahns start receiving mail-in ballots next week and start to make up their minds.

Huntsman owned a slim edge over Cox in previous Deseret News/Hinckley Institute polls.

While the latest results were based on voters who say the would definitely vote in the primary, the race between Huntsman and Cox tightens when those who say they would be very likely vote are added to the mix.

In that case, Cox gets 28% and Huntsman 24%. Hughes comes in at 18%, while Wright stays at 4% and 26% aren’t sure who they would vote for.

Pollster Scott Rasmussen queried 494 likely primary voters from May 25-31. Of that number, 261 came from list of those who voted in the previous primary election, while the remaining 233 came from general voter lists and a screening process. All of them said they would definitely vote in the GOP primary. The poll has a margin of error of plus or minus 4.4 percentage points.

Rasmussen also added another 149 respondents who said they were very likely to vote in the primary.

Former Gov. Jon Huntsman Jr. addresses the press following a Utah gubernatorial Republican primary debate at the PBS Utah studio at the University of Utah in Salt Lake City on Monday, June 1, 2020. | Ivy Ceballo, Deseret News

“What this tells us is if the electorate for this primary looks a lot like it did the last time around, if it’s essentially the same voters or voters like that, then results are stronger for Cox,” Rasmussen said.

“If you have an expanded electorate, more people get involved either because of the pandemic or any other reason, Huntsman does better in that situation.”

The independent pollster said he’d love to know who’s going to vote, but nobody does. The poll, though, can focus on the different levels of potential turnout. Eighty-seven percent of respondents identified themselves as Republican.

Huntsman is running ads on social media featuring his daughter, Abby, urging supporters to “make your vote count in June” by ensuring they are registered with the GOP since the party only allows members to participate in the primary.

Former Utah Democratic Party Chairman Jim Dabakis said he’s already switched his party affiliation so he can vote for a still-unchosen GOP gubernatorial candidate in what he has called a “rigged election” because of Republican Party rules. Democrats have long allowed any voter to participate in their party primaries.

Because of COVID-19, the primary election will be conducted entirely by mail. Just seven of the state’s 29 counties have opted to set up what’s being called mobile voting — driving up to a designated location on Election Day and requesting a ballot that must be filled out elsewhere and returned by mail or to a drop box.

The poll showed that 51% of respondents who strongly approve of the job Gov. Gary Herbert is doing would vote for Cox, while only 18% support Huntsman. Among those who somewhat approve of Herbert, only 19% favor Cox, while 30% back Huntsman.

“That suggests his opinion has a pretty significant role in the race,” Rasmussen said of Herbert, who has endorsed Cox.

That endorsement is among several factors that bumped Cox into the lead, said Jason Perry, director of the Hinckley Institute of Politics at the University of Utah.

Utahns generally feel Herbert has done a good job in dealing with the coronavirus pandemic, and Cox has been the mouthpiece on the state’s response and how it emerges from the crisis, he said.

“I think those things really played to his favor over the past two weeks,” Perry said.

Cox called the poll “very encouraging” and reflective of the grassroots support his campaign has earned over the past year.

“It has been exciting to witness thousands of Utahns join our Endorsed by Utah campaign in just a few short weeks, individuals from every corner of our state, from Gov. Herbert to mayors to school board members to everyday citizens. Every single endorsement is important to me and I am grateful for their vote of confidence,” he said in a statement.

Huntsman campaign manager Lisa Roskelley said with unemployment quadrupling over the past two months, Huntsman is focused on sharing his vision to get Utahns back to work and on a path to double the state’s economy.

“If this poll shows anything it is that this race is still in the hands of the voters and that all Utahns who vote for Republicans should make sure they’re registered and send in their ballot before June 30,” she said.

Hughes’ big leap — 14 points since the GOP state convention in April — is the largest among the four candidates. Perry said a lot of that is tied to Utahns’ overall approval of President Donald Trump.

Hughes also jumped up to second behind Cox among those who voted in the previous GOP primary election, the survey shows. Rasmussen said Hughes has made “huge strides” among that group.

Cox has been “omnipresent” in the media as head of the state’s coronavirus task force, said Greg Hartley, Hughes campaign spokesman.

“Despite this, or maybe because of how he’s handled it, the momentum with Republican Primary voters is behind Greg Hughes. The trend in every poll has shown that as voters make up their minds, the vast majority disproportionately come our way,” he said.

Since Rasmussen’s first poll in January, Hartley says Hughes has gained three-fourths of previously undecided voters.

“As that pattern continues — and it will — Hughes will win the primary,” he said.

Wright said his internal polling, “done with credible methodology,” shows he and running mate Congressman Rob Bishop can win the race when Utahns get to know them.

“We’re talking about the same unresolved issues today that we have been for the last 16 years. Inefficiencies and no-bid contracts while we cycle through the same leaders who have had an opportunity to deal with the issues facing our state. It’s time for a change,” Wright said in a statement.

Perry said the close contest, especially with Hughes coming on, highlights the plurality issue. The poll numbers are close enough that any of them could make a difference if they generate some movement or enthusiasm to get people to the polls.

With four candidates vying for the nomination, it’s likely the winner will have less than 50% of the vote, probably closer to 30% to 35%.

“Based on history in the state of Utah, that could be the general election right there,” he said.

Utah last elected a Democratic governor in 1980. The winner of the GOP primary faces Democrat Chris Peterson, a University of Utah law professor.

“This is a close one. This plurality issue will be at play. If voters care about one particular candidate, this is not going to be the primary election to skip turning in your ballot,” Perry said.

Rasmussen said turnout is everything in a race like this.