Almost 24% of Idaho’s registered voters voted in primary election, initial estimates show

BOISE (Idaho Capital Sun) — Roughly 23.9% of Idaho’s registered voters cast ballots in Tuesday’s primary election for state legislative, congressional and county offices, according to initial estimates from state elections officials.

That’s on par with Idaho’s previous primary election turnout, Idaho Secretary of State Phil McGrane told the Idaho Capital Sun on Wednesday.

“One of the interesting insights from yesterday is just there were a lot of efforts to increase turnout and increase participation in the primary,” McGrane said. “Starting with our office doing an ad campaign to let Idahoans know about the election.”

Candidates and political action committees also spent more to drive turnout, he said, along with competitive precinct committee races. 

“And yet, as the dust kind of settles, it looks like turnout was kind of where it normally would be,” McGrane said.

The early voter turnout rate for this year’s primary election doesn’t include Election Day voter registration figures. McGrane said he doesn’t expect the final number to change much. Counties must share that information with his office by next week, he said.

Tuesday’s primary election results won’t become official until they are certified by the State Board of Canvassers. The canvass is scheduled at 11:15 a.m. June 5 in Idaho Falls at the Mountain America Center, McGrane said Tuesday. 

Idaho’s estimated 23.9% primary voter turnout rate this year surpassed the 2016 primary’s 22.95% voter turnout rate, but fell below voter turnout for Idaho’s three primary elections since then. 

Idaho’s average primary voter turnout rate was 27.9% since 2000, excluding the 2024 rate.

In the 2024 primary, voter turnout rates varied across Idaho’s 44 counties, from as low as 16.3% in Nez Perce County in North Idaho and as high as 55.3% in Camas County in south central Idaho, home to around 1,000 people.

In Ada County, Idaho’s most populated and home to Boise, 18.5% of registered voters cast ballots, along with 20.5% of voters in nearby Canyon County, home to Nampa.

It’s difficult to compare turnout rates to recent years, following an all-absentee election in 2020 due to the COVID-19 pandemic and historic primary turnout in 2022 that also featured statewide races, Boise State University political science professor Jaclyn Kettler told the Sun on Wednesday. 

And as Idaho’s population has rapidly grown in recent years, Idaho’s voter registered voter rolls have also grown, surpassing 1 million voters.

Republicans make up 59% of Idaho registered voters, or more than 585,000 people, according to the Idaho Secretary of State’s Office. Unaffiliated voters make up 27% or more than 273,000 of Idaho’s registered voters. Over 125,000 Democrats comprise 13% of Idaho registered voters.

Idaho’s 2024 primary also saw contested and competitive elections that might have helped motivate people to vote, Kettler said. Fifteen Republican state legislators — including the top Senate Republican Chuck Winder — lost re-election campaigns Tuesday, the Idaho Capital Sun reported. 

Idaho primary was two days before Idaho Democratic presidential caucus

This year in Idaho, party caucuses — rather than state-run primary elections — were used to select presidential party nominees. Idaho Republican Party Chairman Dorothy Moon announced former president Donald Trump won Idaho’s GOP delegates. The Idaho Democratic Party is holding its presidential nominating caucus from 5-8 p.m. today.

Idaho has had separate primaries for presidential and state elections since 2016, McGrane said. This year, following Idaho’s shift to caucuses, there has been concern about confusion around election dates.

McGrane said election officials received some questions about the presidential primary early Tuesday, but that it wasn’t a large volume.

“For us and the county clerks, we were nervous about that headed in and that being a major impact. I think it could’ve been,” McGrane said. “… But I think in talking to … other secretaries of state around the country … because the presidential election has been locked up for such a long period of time, voters have kind of just accepted the nominees being President Biden and President Trump headed in. And so there isn’t a lot of focus on that at this point in time. I think if it was a more open, competitive presidential election, that would be different.”

While some states had seen a drop in primary turnout since, McGrane said he doesn’t think it happened in Idaho. But the uptick in turnout some anticipated based on local developments also didn’t happen, he said.

“I think maybe, to some degree, the two things canceled each other out. … You saw a lot of money, a lot of effort here in terms of the ground games for precinct committee people and other things, helping potentially increase turnout. But then it was also muted because there wasn’t an active presidential election that would have normally brought further turnout,” McGrane said.

​​In Idaho, Republican primary elections often decide major elections. Idaho voters last elected a Democrat to statewide office in 2002. Since 1992, Republicans have held a supermajority in both chambers of the Idaho Legislature. 

Primary elections — when candidates compete for political party endorsements — tend to have lower turnout than general elections, when voters cast final votes for races. Primaries tend to draw voters among the party’s base, Kettler said, who can be more motivated or more ideologically extreme.