BOISE — The tech company office where Mikelle Oliver works as a recruiter opened two and a half years ago and is now so crammed she must share a desk.
Ms. Oliver and her 200 co-workers will soon move to another building and be joined by 300 more employees. A housing development of 3,000 homes on Boise’s edge, planned for a 20-year build-out, is about a decade ahead of schedule. On the city’s hippest strip, young people pack the outdoor cafes on a late spring weeknight.
These are heady times for Idaho’s biggest metro area, with an influx of newcomers, a spike in home prices and a jolt of high-wage jobs in professions like payroll services and accounting that have made Idaho the fastest-growing state in the nation. Boise has driven the growth — more than four in 10 Idaho residents now live within a half-hour’s drive of the State Capitol in the heart of the city.
With that wave of urbanization and economic development has come a new political chemistry in this conservative rural state. Idaho’s new residents, clustering in Boise’s boom zone, are creating uncertainty about how they might vote in Tuesday’s primary for governor in a moment when economics, politics and demographics are all in motion.
No one is expecting a revolution; the long dominance by Republicans is almost certainly secure. Still, political experts said, the election could be pivotal for both parties as a measure of whether prosperity and new blood push Democrats and Republicans toward moderation, or away from it.
Sam McMahon, 22, who grew up east of Seattle and graduated this spring with a degree in computer science from Boise State University, is among the new deciders. He described himself as an enthusiastic but uncommitted Democrat who planned to vote on Tuesday in a primary where the open seat for governor is the headline attraction. Boise’s mayor, Dave Bieter, a Democrat, said newcomers like Mr. McMahon were making some traditionally Republican state legislative seats on the city’s edge competitive for the first time in recent memory.
Tiffany Amos also plans to vote. She came to Idaho from California for college, and she and her husband have put down roots, buying a home here last summer. She said she planned to vote for a Republican but hasn’t decided who will get her support in a crowded field. Gov. C. L. Otter, a Republican known to all as Butch, is retiring after 12 years.
Many residents — some in frustration, others with a sigh of relief — said they thought that Idaho could emerge from this election cycle superficially unchanged, shifted only in the nuances and margins despite the churn of new wealth, new population and anxiety about where it all might lead.
More economic energy than ever is flowing from Boise, but the legislature is likely to remain firmly in the grip of conservative rural lawmakers. More retirees are moving in for the attractive home prices and taxes, but so are more young tech workers who want good schools. Democrats have felt a surge of enthusiasm in the city itself, but Republicans have seen even more as new conservatives from places like Southern California have flocked to the suburbs.
“People keep thinking, ‘Oh, you’ve got all these people moving in, it’s going to kind of moderate and you’re going to get a two-party system,’” said Gary Moncrief, a retired professor at Boise State University who has studied the state for 40 years. “People have been talking about that now for 30 years and it just hasn’t happened, and part of that is because of the nature of the people that are moving here.”
In the primary, almost all the candidates for governor are reaching out in various ways to the altered electorate, either to suggest that greater change is possible now in a boom economy, or that the line against further change will be defended.
For the Democrats, a Boise businessman, A. J. Balukoff, is pledging to fight for improved health care and more education spending, and is facing an insurgent progressive to his left in Paulette Jordan, a former state legislator who is the first Native American to run for governor in Idaho. Ms. Jordan promises to raise the minimum wage and fight climate change.
On the Republican side, the three leading candidates are making pitches to very distinct segments of the electorate, and tapping into concerns about where the state might be headed. Raúl Labrador, a congressman from the Boise suburbs, is running on conservative issues like abortion and gun rights. Tommy Ahlquist, a physician and businessman who has had a hand in the boom as a developer, is pledging more economic growth. Brad Little, the lieutenant governor, is appealing to voters who want an experienced hand at the helm.
If new voters do in fact tip any of Tuesday’s outcomes, it will be the voice of the West Coast — liberal, conservative or something between — that rises above the din. Los Angeles County has in recent years sent more residents to Ada County, which includes Boise and its western suburbs, than any other place. Utah County in Utah and San Diego and Orange Counties in California are close behind.
“It’s a fascinating election — I think a lot of people are going to be poring over the numbers the day after, and the day after that, because everyone is anxious to understand what shift is really occurring,” said Jeff Sayer, a former director of the Idaho Department of Commerce.
Some changes are already here, and for longtime residents, drenched with meaning and symbolism. The Boise Co-op, for example, a beloved 45-year-old symbol of the North End — generally considered the city’s most liberal neighborhood — spent $3.5 million to open a grocery store in Meridian, 10 miles to the west, where conservative politics run deep and California license plates are common.
The Meridian store now outpaces the original during membership drives, sometimes by a three-to-one margin, and attracts shoppers like Ashley and her husband, Ray, transplants from the San Francisco area who did not want their last names used because of a backlash they say is running hot against Californians. They left California last year, they said, seeking a more conservative environment in which to raise their children, ages 9 and 3. “We just didn’t agree with California politics,” Ashley said.
Whether voters in the midst of a boom move left or right, many residents say the strains of change are deep, as farms and ranches on the city’s edge get chewed up into housing, and high-wage tech workers outcompete the locals. Klea Gentle, a hotel sales manager, said the frustrations of shopping for a home in Boise’s North End, and getting beaten by cash offers far above the asking price, were shocking in a once quiet market.
Ms. Gentle is a Democrat who said she has found herself moving to the left and will vote for Ms. Jordan. Politicians and economists said they have been looking at how other Western cities handled urban booms before Boise’s, from Denver to Salt Lake City.
Ms. Oliver, 29, the tech recruiter, said it feels like a bubble.
“There are not enough companies to sustain the amount of growth we’re seeing, and salaries are not keeping up,” she said. She described herself as Republican-leaning but undecided in the governor’s race. In any case, she added, political change is inevitable sooner or later from the wave of new people. “I don’t think we’ve seen it yet, but it’s definitely coming,” she said.
Her employer, Paylocity, an Illinois-based company that expanded in Idaho in 2015, will continue its growth curve outside Boise. The company is taking space in Meridian, which is now Idaho’s second-largest city, grown from sleepy farm roots within a generation and now home to one of the busiest traffic intersections in Idaho, footsteps from the Boise Co-op.