PHOENIX - Arizona State Treasurer Jeff DeWit is joining Donald Trump's presidential campaign as chief operating officer, running the administrative and organizational operations, the Trump campaign announced Wednesday.

DeWit told 12 News Wednesday morning that he would keep his $70,000-a-year job as treasurer while working on the Trump campaign.

When asked via text message if he was quitting, DeWit responded: "I love serving Arizona, absolutely not! Just volunteering my free time to help Make America Great Again!"

"It's not a job per se, just helping out a friend's campaign. I can do a lot from AZ."

DeWit was Trump's Arizona campaign chairman and a frequent television surrogate for Trump. He has also been part of the Trump team at campaign events around the country.

The celebrity billionaire won a resounding victory in the Arizona primary March 22, taking 47 percent of the vote.

DeWit was the first elected official in the country to endorse Trump after he announced his run for president in June 2015. A month later, DeWit met with Trump on the candidate's jet in Phoenix, where Trump encouraged DeWit to challenge Sen. John McCain.

The first-term Republican had announced in April, just 18 months into the job, that he wouldn't run for re-election in 2018.

DeWit ran a stock-trading company and was a politically active Republican before making his first run for office in 2014.

He thrust himself into the center of the recent debate over Proposition 123, opposing the ballot measure to pump more than $2 billion into Arizona schools by tapping the state land trust fund. As treasurer, DeWIt chairs the State Investment Board, which oversees the fund.

DeWit's opposition to Prop 123 led to a bitter clash with GOP Gov. Doug Ducey, a former state treasurer who came up with the idea.

DeWit will be succeeded as Trump's Arizona campaign chair by State Rep. Phil Lovas of Peoria. Lovas' wife, Corinne Lovas, is a top fundraiser for McCain and other Republicans.