This November, Iowans will be asked to vote on a simple constitutional amendment on whether the legislature should obtain a two-thirds majority in both houses to increase income taxes. The amendment is simple because the problem it solves is simple. Raising income taxes shrinks the paychecks of workers and cuts into the bottom line of farms and businesses of all sizes. A decision like this, which directly and immediately affects the livelihood of Iowans, should not be something that lawmakers can do without broad consensus or accountability.
Politicians too often have a difficult time limiting spending on their own. One of us, former Wisconsin state legislator Leah Vukmir, has seen that dynamic firsthand. When spending continues to grow, lawmakers eventually face pressure to find more tax revenue to pay for it.
That is why a supermajority requirement can serve as a practical check on the growth of government. By making it more difficult to raise income taxes, the amendment would encourage lawmakers to exercise greater discipline on the spending side of the ledger, examining existing spending, prioritizing programs, and seeking efficiencies before turning to taxpayers for additional revenue.
At its core, the two-thirds requirement is a protection for taxpayers. Tax revenue comes from the earnings and economic activity of Iowa families, workers, farms, and businesses. Clearing a higher bar before the state can take more of those earnings is a worthwhile safeguard. Raising income taxes should be difficult, and it should be harder than it is today.
Supermajority requirements to raise taxes are not new. Sixteen states already operate under some form of supermajority requirement, including states as politically different as California, Arizona, and Wisconsin.
In 2011, the Wisconsin legislature passed Act 9, which established a supermajority requirement for both the House and Senate to increase taxes. Specifically, Act 9 states that the legislature cannot increase “the rate of the state sales tax or that increases any of the rates of the income tax or franchise tax unless the bill is approved by two-thirds of those members present and voting.” In Wisconsin, this crucial protection was important for building broad legislative support rather than pushing tax increases through on a narrow partisan basis.
That broader consensus is an important feature of a supermajority requirement. Lawmakers must make a stronger case for raising taxes and persuade a larger share of their colleagues that an increase is necessary. In many circumstances, that means securing support from legislators across party lines.
The alternative can be seen when growing spending creates persistent pressure for additional revenue. Washington, which historically had no individual income tax, recently enacted a new tax on income as lawmakers confronted a significant budget shortfall following years of spending growth. It illustrates why controlling spending matters: when expenditures consistently outpace available revenue, pressure to find new sources of tax revenue inevitably grows.
At its core, this amendment is about restoring balance. Government will always face pressure to spend more, but taxpayers deserve a system that requires real justification before asking them to give more. A two-thirds requirement ensures that higher taxes are the last resort, not the first response, when budgets tighten. It shifts the burden back where it belongs: on government to prioritize, manage responsibly, and live within its means.
By embedding that principle in the Constitution, Iowa can provide lasting protection for taxpayers and reinforce a simple but essential truth: the money belongs to the people first, not the government. ITR Foundation’s founder, David Stanley, stated that a supermajority requirement “would give Iowa taxpayers permanent protection and politicians an allowance instead of a blank check.” Wisconsinites and taxpayers of 15 additional states have discovered this truth. It’s time for Iowans to join them.