"I've sometimes rubbed the Republican Party wrong. There's a lot [of people] in the party that are not supportive of me," he said. "I frankly didn't feel like I'd get a fair shot in the Republican caucus system."
Before his membership in the Elephant Club and his term as a Republican delegate, Curtis was for a short time registered as a Democrat when he unsuccessfully ran against state GOP Sen. Curt Bramble in 2000. Still, Curtis' anti-abortion, pro-gun rights platform was typically conservative with a nod to moderate politics.
He later returned to the Republican Party and launched a special election campaign for retiring state Rep. Jeff Alexander's seat in 2007. Though he had one more delegate vote than Chris Herrod, the governor appointed Herrod. (The former lawmaker is now among the candidates seeking to replace Chaffetz).
Curtis then turned his attention to local government. He won his first term as Provo mayor, a nonpartisan office, in 2009.
In recent weeks, conservatives across the state have criticized the two-term mayor of the state's third largest city for temporarily leaving the GOP.
"I didn't really change my principles," he explained Thursday, "but I changed where I was trying to make them applicable. Parties are important, but they're not always first."
While Curtis still plans to give a speech at the convention, he's already qualified for the Aug. 15 primary. He submitted more than 15,000 signatures to the state elections office Monday and joins investment adviser Tanner Ainge (son of Boston Celtics General Manager Danny Ainge) on the ballot.
A third Republican hopeful is expected to be selected at Saturday's GOP convention. Front-runners for the convention nod include state Sens. Deidre Henderson and Margaret Dayton and state Rep. Brad Daw.
Chaffetz plans to step down from his seat June 30. Some 21 candidates are currently in the race to replace the congressman.