Sandra Hollins also won a three-way race toward filling the seat of retiring House Minority Leader Jennifer Seelig, D-Salt Lake City. Hollins now has a good shot at becoming Utah's first-ever black woman legislator, since her House District 23 leans heavily Democratic.
Another bid for history fell short Saturday. Sophia Hawes lost her campaign to become the Utah party's first-ever transgender nominee.
Across the valley in the Republican County Convention, delegates ousted one-term county auditor incumbent Greg Hawkins and Rep. Jim Bird, R-West Jordan. Bird, a four-term incumbent, was knocked out by Kim Coleman, a GOP activist and political consultant. She is the founder of Monticello Academy, a charter school.
In the three-way race for the Republican nomination to replace retiring Democratic County Councilman Randy Horiuchi, Micah Bruner won with 71 percent of the vote.
If he defeats Horiuchi's chosen Democratic successor, Jenny Wilson, it would give Republicans a veto-proof majority on the council.
In addition to picking candidates, Republican delegates listened to political speeches, including one from a tough-talking Sen. Orrin Hatch.
"We've simply got to change some of the domestic policies above all, above all, this incredibly poor I don't usually use these words but dumb-ass Obamacare," said Hatch.
Among Democrats, the race between Iwamoto and Romero was the most hotly contested in Salt Lake County a place that is sort of a Fort Apache, last-stand area for the party that has the only elected Democratic legislators in the state.
Romero and Iwamoto had waged the most expensive legislative race in either party so far, with Romero raising $31,000 and Iwamoto raising $27,000 before the convention. With that, they offered the only hospitality rooms for delegates Saturday feeding them pizza, snacks and drinks all day.
Most people expected results to be close, and force a primary. Romero's campaign chairman, Jason Wessel, said Iwamoto clinching the nomination at convention was "a shock." Wessel had a doubly bad day. He also was one of the losing candidates in the House District 23 race to Hollins.
Iwamoto sought and won strong support from women including formal endorsement by the Democratic Women's Caucus and she argued that more women are needed in the Legislature, and her race is to replace a woman there.
"We have a proud tradition of electing women in this district," she said.
Iwamoto told delegates that her old County Council seat also was entirely within Senate District 4, so she has shown she can win it a reference to how Romero's old legislative seats were only partially in the area before redistricting.
"I've won this district before, and I can do it again with your support," she said.
She will face Sabrina Petersen, a Holladay City councilwoman, who clinched the Republican nomination at Saturday's GOP convention.
Meanwhile, Hollins managed to win 69 percent of the vote in a second round of voting against Wessel, sending her to the November election. Candidate Frank Bedolla was eliminated in a first round.
"I would be the first black woman in the Legislature," Hollins said. She told delegates she hoped to work on behalf of those "who have nothing, who have been marginalized and those people who, frankly, don't fit into society."
In another interesting race, Associate Deputy Salt Lake County Mayor Justin Miller won a three-way race in House District 40 (where Rep. Lynn Hemingway, D-Millcreek, is retiring) against Sophia Hawes, seeking to become the first transgender nominee, and Amy Fowler, a public defender who is a gay activist.
Miller won 60.3 percent of the vote barely enough to avoid a primary.
Hawes told delegates in her losing cause, "For too long, Utah's marginalized communities have stood in the shadows eagerly accepting crumbs from a Legislature that neither understands nor values their contributions."
Former County Auditor Jeff Hatch and Christopher Stout will face each other in a June 24 primary for what may be a surprisingly spirited race.
The winner of that runoff will face Republican newcomer Scott Tingley, who knocked off one-term incumbent Hawkins.
Tingley sharply criticized Hawkins' "checklist" method of auditing and promised to improve the office's relationship with the County Council.
The GOP convention was tough for one more incumbent. Assessor Kevin Jacobs was forced into a primary election by Jake Parkinson. The winner will face Democrat Tyler Andrus in November.
Salt Lake County highlights, Democratic and Republican conventions
Those with more than 60 percent, shown in bold, advance to the general election. Otherwise, the top two candidates face off in a primary.
Senate District 4 • Democrat Jani Iwamoto, 62%, Ross Romero, 38%. Republican Sabrina Petersen, 75%; Philip Carlson, 25%.
House District 23 • Democrat Sandra Hollins, 69%, Jason Wessell, 31%. Faces Republican Kristopher Smith in November.
House 30 • Republican Fred Cox 69%, Carbon Lundgren, 31%. Faces Democrat Michael Lee in November.
House 40 • Democrat Justin Miller, 60%; Amy Fowler, 32%; Sophia Hawes, 8%. Faces Republican Peter Kraus in November.
House 42 • Republican Kim Coleman, 72%; Jim Bird, 28%. Will face Democrat Nicholas Deland in November.
House 44 • Republican Bruce Cutler, 65%; John Jackson, 35%. Will face Democrat Christine Passey in November.
S.L. County auditor • Republican Scott Tingley, 69%; Greg Hawkins, 31%. Democratic primary between Christopher Stout, 54%, Jeff Hatch, 46%.