| David Scott | American Council of Engineering Companies | Opposing | GA88 |
| Drew Klein | Americans For Prosperity | Undecided | GA88 |
| Tyler Raygor | Americans For Prosperity | Undecided | GA88 |
| Scott Newhard | Associated General Contractors of Iowa | Opposing | GA88 |
| Tim Reilly | Department of Revenue | Undecided | GA88 |
| Dawn Carlson | FUELIowa (PMCI) | Undecided | GA88 |
| Kellie Paschke | FUELIowa (PMCI) | Undecided | GA88 |
| Troy Skinner | FUELIowa (PMCI) | Undecided | GA88 |
| Pam Mackey-Taylor | Iowa Chapter of Sierra Club | Opposing | GA88 |
| Lyle Brehm | Iowa County Engineers Association | Opposing | GA88 |
| David Scott | Iowa Engineering Society | Opposing | GA88 |
| David Scott | Iowa Good Roads Association | Opposing | GA88 |
| Alan Kemp | Iowa League of Cities | Undecided | GA88 |
| Daniel Stalder | Iowa League of Cities | Undecided | GA88 |
| Robert Palmer | Iowa League of Cities | Undecided | GA88 |
| David Scott | Iowa Motor Truck Association | Opposing | GA88 |
| Mike Heller | Iowa Renewable Fuels Association (IRF) | Undecided | GA88 |
| Nathan Hohnstein | Iowa Renewable Fuels Association (IRF) | Undecided | GA88 |
| Paula Feltner | Iowa Renewable Fuels Association (IRF) | Undecided | GA88 |
| Jamie Cashman | Iowa State Association of Counties | Opposing | GA88 |
| Kristi Harshbarger | Iowa State Association of Counties | Opposing | GA88 |
| Lucas Beenken | Iowa State Association of Counties | Opposing | GA88 |
| William Peterson | Iowa State Association of Counties | Opposing | GA88 |
| Jamie Cashman | Iowa State Association of County Supervisors | Opposing | GA88 |
| Kristi Harshbarger | Iowa State Association of County Supervisors | Opposing | GA88 |
| Lucas Beenken | Iowa State Association of County Supervisors | Opposing | GA88 |
| William Peterson | Iowa State Association of County Supervisors | Opposing | GA88 |
| Kate Walton | POET, LLC | Undecided | GA88 |
| Matt Eide | POET, LLC | Undecided | GA88 |
| Mike Heller | Petroleum Marketers Management Insurance Company (PMMIC) | Undecided | GA88 |
| Paula Feltner | Petroleum Marketers Management Insurance Company (PMMIC) | Undecided | GA88 |
| David Scott | Society of Land Surveyors of Iowa | Opposing | GA88 |