Huntsman served as governor from 2005 to 2009. He was seen as a likely 2012 presidential candidate before resigning to become then-President Barack Obama's ambassador to China.

But Huntsman left Beijing in 2011 and ran for the GOP nomination anyway, failing to gain any real traction within the Republican primary. In the Trump administration, Huntsman served as ambassador to Russia for two years starting in October 2017.

Although he served in the Trump administration, Huntsman's public persona remained sanguine and drawn to moderation.

Huntsman had been mentioned as a top prospect within the Republican primary for governor. His entrance adds to the number of competitors in the field. Lt. Gov. Spencer Cox is running, as is Salt Lake County Counctilwoman Aimee Winder Newton and businessman Jeff Burningham.

Cox has the endorsement of retiring GOP Gov. Gary Herbert, who replaced Huntsman in 2009 and declined to run for a third full term next year.

The few surveys of the race indicate that Huntsman and Cox would be the two most competitive candidates. A Salt Lake Chamber poll found Huntsman with 30 percent support among Republican voters, compared to 34 percent for Cox.

In his announcement Thursday, Huntsman alluded to his experience as a governor, a likely prominent theme in his candidacy. Prior to resigning in 2009, Huntsman's approval ratings were as high as 84 percent.

"Just to put it in a nutshell, I believe that we face an inflection point as a state," Huntsman said. "I think that the years ahead are going to be absolutely critical, and the choices that we make are going to shape the future for years to come. That's what governors do. They look into the future. They anticipate what our needs are going to be. They assemble the best people we can find, and they make choices that aren't immediate but resonate for a very long time."