2026 ballot measure forecast
Iowa Amendment 1
Two-thirds legislative vote to raise income taxes
Requires a two-thirds vote of both chambers of the Iowa General Assembly to raise individual or corporate income tax rates or to create a new tax on income. The forecast has Yes at 51.9 percent against the 50 percent it needs, a 63% chance to pass.
Chance to pass
63%2,000 simulations
Forecast Yes
51.9%80% range 45 to 59
Needs
50%a simple majority
Polling average
46.5%Yes, with undecided split two to one for No
Where the Yes vote lands
needs 50
2035506580- History and structure
- 65.2% Yes
- Polls
- 46.5% Yes
- Forecast
- 51.9% Yes
- Yes leans
- Republican
- Rule to pass
- Simple majority of those voting on the amendment. Passed GA twice (HJR 2006 in 2024, SJR 11 in 2025-26) on party-line votes.
The campaign
Yes: Iowans for Tax Relief and GOP legislators. No: Fair Taxes for Iowa's Future coalition (Common Good Iowa, Iowa State Education Association, labor). No dollar figures reported.
No +30Yes +30Click a county to zoom · arrow keys step through counties by size
Where the margin is won
Yes +90,266 net votes from 92 countiesStatewide Yes +3.8, a 49,096 vote marginNo +41,170 net votes from 7 counties
Projected vote
1,288,848 votes on the question| Choice | Votes | Share |
|---|---|---|
| Yes | 668,972 | 51.9% |
| No | 619,876 | 48.1% |
| Total | 1,288,848 | 100% |
| County | Yes | No | Total | Yes share |
|---|---|---|---|---|
| Polk County | 93,073 | 108,227 | 201,300 | 46.2% |
| Linn County | 45,034 | 51,901 | 96,935 | 46.5% |
| Scott County | 34,282 | 34,820 | 69,102 | 49.6% |
| Johnson County | 26,891 | 40,814 | 67,705 | 39.7% |
| Black Hawk County | 24,418 | 25,973 | 50,391 | 48.5% |
| Dallas County | 23,159 | 23,341 | 46,500 | 49.8% |
| Dubuque County | 20,841 | 20,278 | 41,119 | 50.7% |
| Story County | 18,734 | 21,685 | 40,419 | 46.3% |
| Pottawattamie County | 17,764 | 15,543 | 33,307 | 53.3% |
| Woodbury County | 17,746 | 15,081 | 32,827 | 54.1% |
| Warren County | 13,218 | 11,479 | 24,697 | 53.5% |
| Clinton County | 9,603 | 8,487 | 18,090 | 53.1% |
| Cerro Gordo County | 9,116 | 8,621 | 17,737 | 51.4% |
| Jasper County | 8,614 | 6,997 | 15,611 | 55.2% |
| Marion County | 8,626 | 6,313 | 14,939 | 57.7% |
| Sioux County | 10,148 | 4,729 | 14,877 | 68.2% |
| Muscatine County | 7,711 | 7,072 | 14,783 | 52.2% |
| Des Moines County | 7,590 | 6,955 | 14,545 | 52.2% |
| Marshall County | 7,015 | 6,395 | 13,410 | 52.3% |
| Webster County | 7,341 | 5,757 | 13,098 | 56.0% |
| Lee County | 6,832 | 5,527 | 12,359 | 55.3% |
| Boone County | 6,274 | 5,405 | 11,679 | 53.7% |
| Benton County | 6,510 | 4,999 | 11,509 | 56.6% |
| Wapello County | 6,401 | 5,004 | 11,405 | 56.1% |
| Bremer County | 6,108 | 5,234 | 11,342 | 53.9% |
| Plymouth County | 6,456 | 3,899 | 10,355 | 62.3% |
| Winneshiek County | 4,865 | 4,703 | 9,568 | 50.8% |
| Washington County | 4,923 | 4,128 | 9,051 | 54.4% |
| Dickinson County | 5,017 | 3,589 | 8,606 | 58.3% |
| Mahaska County | 5,257 | 3,285 | 8,542 | 61.5% |
| Jones County | 4,685 | 3,853 | 8,538 | 54.9% |
| Carroll County | 5,015 | 3,509 | 8,524 | 58.8% |
| Buchanan County | 4,633 | 3,740 | 8,373 | 55.3% |
| Cedar County | 4,384 | 3,769 | 8,153 | 53.8% |
| Jackson County | 4,576 | 3,539 | 8,115 | 56.4% |
| Poweshiek County | 4,133 | 3,720 | 7,853 | 52.6% |
| Delaware County | 4,540 | 3,256 | 7,796 | 58.2% |
| Fayette County | 4,354 | 3,436 | 7,790 | 55.9% |
| Madison County | 4,441 | 3,224 | 7,665 | 57.9% |
| Iowa County | 4,126 | 3,347 | 7,473 | 55.2% |
| Henry County | 4,275 | 3,188 | 7,463 | 57.3% |
| Clayton County | 4,195 | 3,180 | 7,375 | 56.9% |
| Hardin County | 3,933 | 2,863 | 6,796 | 57.9% |
| Tama County | 3,730 | 3,050 | 6,780 | 55.0% |
| Clay County | 3,951 | 2,726 | 6,677 | 59.2% |
| Kossuth County | 3,965 | 2,705 | 6,670 | 59.4% |
| Jefferson County | 3,346 | 3,308 | 6,654 | 50.3% |
| Butler County | 3,688 | 2,484 | 6,172 | 59.8% |
| Mills County | 3,556 | 2,568 | 6,124 | 58.1% |
| Floyd County | 3,246 | 2,687 | 5,933 | 54.7% |
| Hamilton County | 3,341 | 2,565 | 5,906 | 56.6% |
| Harrison County | 3,472 | 2,429 | 5,901 | 58.8% |
| Allamakee County | 3,304 | 2,509 | 5,813 | 56.8% |
| Buena Vista County | 3,257 | 2,501 | 5,758 | 56.6% |
| O'Brien County | 3,655 | 2,016 | 5,671 | 64.5% |
| Page County | 3,332 | 2,322 | 5,654 | 58.9% |
| Grundy County | 3,261 | 2,283 | 5,544 | 58.8% |
| Cass County | 3,207 | 2,272 | 5,479 | 58.5% |
| Lyon County | 3,496 | 1,673 | 5,169 | 67.6% |
| Guthrie County | 2,933 | 2,142 | 5,075 | 57.8% |
| Appanoose County | 3,004 | 1,992 | 4,996 | 60.1% |
| Crawford County | 2,941 | 2,025 | 4,966 | 59.2% |
| Chickasaw County | 2,843 | 2,096 | 4,939 | 57.6% |
| Shelby County | 2,887 | 1,997 | 4,884 | 59.1% |
| Cherokee County | 2,852 | 1,910 | 4,762 | 59.9% |
| Union County | 2,706 | 2,015 | 4,721 | 57.3% |
| Hancock County | 2,719 | 1,787 | 4,506 | 60.3% |
| Wright County | 2,582 | 1,915 | 4,497 | 57.4% |
| Winnebago County | 2,482 | 1,955 | 4,437 | 55.9% |
| Mitchell County | 2,474 | 1,940 | 4,414 | 56.0% |
| Sac County | 2,558 | 1,599 | 4,157 | 61.5% |
| Calhoun County | 2,416 | 1,602 | 4,018 | 60.1% |
| Keokuk County | 2,444 | 1,530 | 3,974 | 61.5% |
| Humboldt County | 2,399 | 1,529 | 3,928 | 61.1% |
| Montgomery County | 2,227 | 1,608 | 3,835 | 58.1% |
| Louisa County | 2,224 | 1,572 | 3,796 | 58.6% |
| Franklin County | 2,204 | 1,546 | 3,750 | 58.8% |
| Palo Alto County | 2,236 | 1,512 | 3,748 | 59.7% |
| Greene County | 2,111 | 1,625 | 3,736 | 56.5% |
| Emmet County | 2,128 | 1,456 | 3,584 | 59.4% |
| Howard County | 2,014 | 1,570 | 3,584 | 56.2% |
| Lucas County | 2,157 | 1,404 | 3,561 | 60.6% |
| Clarke County | 2,051 | 1,434 | 3,485 | 58.9% |
| Monona County | 2,065 | 1,391 | 3,456 | 59.8% |
| Worth County | 1,819 | 1,469 | 3,288 | 55.3% |
| Adair County | 1,912 | 1,290 | 3,202 | 59.7% |
| Davis County | 1,944 | 1,172 | 3,116 | 62.4% |
| Monroe County | 1,900 | 1,202 | 3,102 | 61.3% |
| Decatur County | 1,780 | 1,173 | 2,953 | 60.3% |
| Van Buren County | 1,794 | 1,064 | 2,858 | 62.8% |
| Pocahontas County | 1,772 | 1,072 | 2,844 | 62.3% |
| Ida County | 1,750 | 1,069 | 2,819 | 62.1% |
| Fremont County | 1,653 | 1,122 | 2,775 | 59.6% |
| Audubon County | 1,441 | 1,046 | 2,487 | 57.9% |
| Wayne County | 1,551 | 898 | 2,449 | 63.3% |
| Osceola County | 1,587 | 830 | 2,417 | 65.7% |
| Taylor County | 1,476 | 876 | 2,352 | 62.8% |
| Ringgold County | 1,285 | 806 | 2,091 | 61.5% |
| Adams County | 987 | 672 | 1,659 | 59.5% |
Projected 2026 votes: each county's expected turnout, less the roughly 6 percent of voters who skip a ballot question, times its forecast Yes share. The measure needs 50.0 percent Yes to pass.
Polls of the measure
2 polls| Pollster | Sample | Ended | Yes | No | Undecided | Yes, adjusted |
|---|---|---|---|---|---|---|
| Suffolk University Political Research Center | 500 LV | 2026-10-04 | 39.6 | 36 | 24 | 47.8% |
| Suffolk University Political Research Center | 500 LV | 2026-08-23 | 33 | 36 | 30 | 43.4% |
How this is built
Amendment 1 is forecast as a income tax measure whose Yes vote leans Republican. Comparable measures from 2018 to 2024 set how far its Yes share moves with Iowa's partisanship and with each county's 2024 presidential vote, and how it reached the ballot moves it further. Polls then pull the forecast toward them by recency and size, after splitting undecided voters two to one for No. Sources: news.ballotpedia.org, iowacapitaldispatch.com, newsfromthestates.com, kcrg.com. All measures.