Yes votes lead for Iowa constitutional amendment limiting income tax increases

Iowa lawmakers are likely to need a supermajority vote to increase personal and corporate income taxes after approval for a proposed constitutional amendment took the lead Tuesday night.

Amendment 1 had received 55% yes votes to 45% no votes with 84% of votes counted as of 12:05 a.m., according to unofficial results from the Associated Press.

The amendment would require a two-thirds majority of both the Iowa House and Senate to increase personal or corporate income taxes.

Supporters, mostly Republicans, said imposing the restriction in the state constitution would preserve GOP-backed tax policies, including 3.8% flat-rate income tax approved in 2025. They argue that lawmakers could still raise the income tax as a last resort but would need broad, bipartisan support.

Democrats and other opponents of the amendment said it would lock in unsustainable tax cuts that largely benefitted Iowa’s highest income earners while creating a billion-dollar state budget deficit. They argue that needed revenue increases would fall on sales taxes and fees that disproportionally affect lower-income Iowans, while spending cuts would hit public schools and services that aid vulnerable residents.

Changing Iowa’s constitution is a multiyear process.  A resolution proposing a constitutional amendment must pass two consecutive general assemblies in identical form before going to voters in a general election.

Amendment 1 would be Iowa’s 52nd constitutional amendment.