"I think this is a great symbol of what we're trying to accomplish," he said, noting that plenty of people told him it couldn't be done.
The elections office will spend the next few days verifying the names. Curtis is the second and last candidate to qualify for the Aug. 15 primary with signatures — pending certification. Tanner Ainge, an investment adviser and son of Boston Celtics General Manager Danny Ainge, submitted nearly 9,000 signatures last week.
Unlike Ainge, Curtis still plans to participate in Saturday's Republican convention. It's expected that one more contender will emerge from that, and the front-runners appear to be state Sens. Deidre Henderson and Margaret Dayton and state Rep. Brad Daw.
That means the primary ballot this year will be unusual with three names from the GOP, rather than the usual two.
Curtis said collecting the signatures, most from Utah County, reaffirmed his decision to join the race.
"It would [seem] to say there are a lot of people who would like to see me on the ballot," he said. "I feel a pretty weighty responsibility not to let them down."
Other candidates found the alternative route to the ballot too daunting. Republicans Shayne Row and Brigham Cottam and Democrats Ben Frank and Carl Ingwell indicated an intent to gather signatures when they filed for office, but none of the four were able to reach the 7,000 requirement. They'll instead try their luck at the convention (though Cottam has decided to run as a write-in candidate).
Thomas, the state elections director, said many filed to both gather signatures and campaign at the convention "just to keep their options open." But time, money and energy can make collecting names difficult — especially during a special election.
"In this case, the schedule was pretty limiting," Thomas said.
Ingwell said he was "overly optimistic" about the signature route when he first submitted his papers. A few days later, he realized "getting those just seemed really unrealistic." With a grass-roots campaign, he found himself short on funds.
Michael Allegrini, manager for Frank's campaign, said his team started collecting names but couldn't get enough before the due date.
"We figured we would try, even though it was an almost insurmountable feat," he said.
Since the filing deadline, three candidates have also dropped out of the race: Republicans Jeremy Friedbaum and Mike Leavitt (who is not the former governor of Utah by the same name) and Democrat Faeiza Javed.
With the addition Monday of one unaffiliated candidate, Sean Whalen, and one write-in, Russell Roesler, that leaves 21 competing for Chaffetz's seat, which the congressman will vacate June 30.