DES MOINES — Iowa Republicans mounted a larger advantage over Democrats in voter registration totals coming out of the June primary, indicating growing strength of the party that has increasingly dominated the state’s elections over the last four years.

Counting both active and inactive voters, there are 782,177 registered Republicans in the state, and 650,112 registered Democrats, as of July 1, according to data from the Iowa Secretary of State's office. There are 768,389 voters registered with no party or with a non-party political organization, while 16,188 are registered as Libertarians.

Active voters are voters that participated in the 2022 election, while inactive voters are those who are registered but did not vote in 2022. They are still eligible to vote in 2024.

Registered Republicans — who make up more than 35% of Iowa voters — now outnumber Democrats in Iowa by more than 130,000. Since this time last year, Republicans gained 33,575 voters, while Democrats lost 22,378.

The June 4 primary, which featured two competitive GOP congressional primaries and saw far higher turnout among Republicans, contributed to the party's gains this year, said University of Iowa political science professor Tim Hagle.

“There were a fair number of party changes in the leadup to the primaries this time, and Republicans tended to benefit from that,” Hagle said. “But they’ve been benefiting by and large for quite a while, several months at least this year.”

Republicans gained 12,659 voters between June and July, while Democrats lost 2,286.

Beyond the primary, the Jan. 15 Iowa caucuses served as a massive organizing boost for the Iowa GOP: the party gained 15,766 voters between January and February, while Democrats lost 5,537 voters in the same month. It was the first month Republicans’ voter advantage crossed 100,000.

No-party voters, who are registered to vote but do not declare a party, grew by 16,784 in the last year. These voters, who tend to lean more conservative, are often the deciding factor in Iowa elections, Hagle said.

Those voters are often less engaged in the day-to-day party politics and more invested in issues like the economy, health care and, more recently, immigration, Hagle said. In recent cycles, they have tended to side with Republicans.

“They’re focused more on economic, kitchen-table type issues,” Hagle said. “So I would say that at least drilling down as far as the congressional district level, it’s still going to be the no-party voters that are particularly important.”

Republicans overtake Democrats in congressional districts

Republicans also outnumber Democrats in each of Iowa’s four congressional districts, a change from July of 2023 when Democrats held advantages in three of the four districts.

Republicans hold all four of Iowa’s seats in Congress. The 1st Congressional District, represented by Rep. Mariannette Miller-Meeks, and the 3rd District, represented by Rep. Zach Nunn, are both seen by Democrats as potential pickup opportunities in the November election.

Party leaders work to mobilize voters

Scott County Democratic Party Chair Kay Pence said the local party has been working to knock doors, engage voters and get them registered to vote as the November election approaches. Pence, who is also running for the Iowa House in a district that includes parts of Scott, Clinton and Jackson counties, said Democratic turnout took a hit in 2022, and they are working to build up turnout.

Despite the registered voter disadvantage, Pence said she thinks Democrats can reach no-party voters by arguing that Republicans have veered too far to the right on issues like education and abortion.

It reflects a broad strategy Democrats have outlined this year of focusing local races on local issues, even as former President Donald Trump leads President Joe Biden in polling by double digits in Iowa and Biden’s recent debate performance has shaken voter confidence in his ability to win the election.

“I think, especially a lot of the no-party people are getting pretty frustrated with what’s going on in Iowa,” Pence said. “I think there’s a lot of people that are upset about (abortion), even people that are beyond reproductive age, because they don’t think the government should be getting in people’s lives.”

A law banning abortion as early as six weeks into a pregnancy, passed by Iowa Republicans in 2023, will take effect this month after the Iowa Supreme Court declared it constitutional and cleared the way for its enforcement. 

Kelly Koch, the chair of the Dallas County Republicans, said the party has been targeting both independents and “soft Democrats,” who are registered as Democrats but may be persuaded to vote Republican.

She said the party is focusing on national issues like the economy, immigration and public safety to message to voters who are disappointed with Biden’s presidency. The local party has put together a “vote red sample ballot” to highlight the Republican candidates on the ticket, she said, which has been mailed to identified voters that may be persuadable.

A June Des Moines Register/Mediacom Iowa Poll found that 50% of likely Iowa voters support Trump in the November election, compared to 32% who said they support Biden. 

“The Biden Administration policies, they don't fit who these people are in Dallas County,” Koch said. “They want safe streets, they want cheaper gas, cheaper Hy-Vee bills … So we are confident with this aggressive plan that we have."