At the Oct. 9, 1912, annual meeting of the Grand Lodge of the Anti Horse Thief Association in Monett, members passed a resolution denouncing a proposed constitutional amendment to restructure Missouri’s tax system.
Backers promised their proposal would ease the burden of government and fire up Missouri’s economic engine by sweeping away almost all state and local taxes in favor of a property tax that applied only to the value of land.
Members of the Anti Horse Thief Association weren’t convinced. Neither were most Missourians. The amendment drew just 14.6% of the vote.
More than a century later, Missouri voters came close to matching that rejection.
Amendment 5, which sought to phase out Missouri’s income tax and allow lawmakers to replace the lost revenue with broader sales taxes, drew just 16.6% of the vote Tuesday — the third-lowest level of support for any constitutional amendment since Missouri adopted the initiative process in 1908.
Amendment 4, another Republican legislative priority, fared only slightly better. The proposal to require citizen-led constitutional amendments to win statewide and in all eight congressional districts received 19.7%.
Both failed in every county in Missouri. The closest either amendment came to winning in a county was Amendment 4 in Shelby County, with a 41.1% “yes” vote.
Missouri voters reject income tax phaseout, initiative petition changes
The magnitude of the defeats has opened a debate over what voters were saying. Republican lawmakers and consultants argue voters rejected particularly flawed versions of ideas their party still supports. Democrats see evidence that the GOP-controlled legislature has drifted away from the voters who put it in power.
House Majority Leader Alex Riley said Republicans won’t try to put Amendment 5 before voters again in the same form. But he still believes Missouri would benefit from eliminating its income tax.
“Those no-income-tax states are crushing it, literally, from every metric right now, and the high tax states are not,” Riley said. “And I would like to be one of those states that is doing much better than we have been.”
Riley, of Springfield, is in line to become House speaker if he wins reelection.
Republicans remain in favor of tax cuts, he said.
“But if we’re going to take another stab at something or another look at something in this income tax space, it’s going to look very very different,” Riley said.
Why they failed
Republican consultants interviewed by The Independent said Amendments 4 and 5 represented deeply unpopular versions of the Republican priorities they were intended to advance.
The goal of Amendment 4— making it harder to amend the Missouri Constitution — is one Republicans have pursued for more than a decade. Lawmakers have considered requiring a higher statewide vote as well as versions requiring amendments to win geographically distributed support.
But requiring a citizen-led amendment to win in all eight congressional districts went too far, said John Hancock, a veteran GOP political consultant. .
“The approach that the legislature chose here was so restrictive that it really never had a chance,” he said.
Sophia Shore, who ran Lori Rook’s successful primary against incumbent state Sen. Curtis Trent in the 20th District, agreed.
“They made it eight out of eight congressional districts and that scares some rural people because we’re going to be ruled by Kansas City and St. Louis now,” she said.
Amendment 4 was passed by lawmakers in the same 2025 special session that revised Missouri’s congressional districts to gerrymander the 5th District into Republican control. Republicans in the state Senate changed the rules to block Democratic filibusters, then used motions to shut off debate before any changes could be offered to the measure that had passed the House on a party-line vote.
“There was zero Democratic input at all on what became Amendment 4,” said state Sen. Stephen Webber, a Columbia Democrat.
Hancock said Republicans could have a different result if they return with a less restrictive proposal and enough money to defend it.
“You need to make sure that you’ve got money assembled to run a supportive campaign, and you’d want to make sure that the standard of amending the Constitution is a reasonable one, say 60% of the vote,” he said. “If you had those two conditions in place, you could have a much different outcome.”
Webber is skeptical voters would embrace even a softer version.
“I’ve never, in all the doors I’ve knocked in my life, come across somebody who says the real problem here is ballot measures and majority rule,” he said. “That’s just not a thing.”
Amendment 5 asked voters to approve the elimination of a tax they understood without telling them precisely what would replace it.
The amendment authorized lawmakers to expand the sales tax to goods and services now exempt from taxation, but it did not spell out which would be taxed or how high the rate could eventually go. Supporters promised the overhaul would be revenue neutral, with new sales taxes replacing money lost by eliminating the income tax.
Shore supports shifting Missouri toward consumption taxes and thinks the state would be better off without an income tax. But she said Amendment 5 left voters with too much uncertainty about who would ultimately pay more.
“Revenue neutral does not mean revenue neutral to the individual middle class taxpayer,” she said. “Revenue neutral is Jefferson City insider talk, but that doesn’t mean that the middle class taxpayer is going to be paying the same rate.”
The proposal also gave future lawmakers wide latitude to decide which industries and transactions would remain exempt from sales taxes, Shore said.
“Why don’t you cap the sales tax and why don’t you say no exemptions out of the gate?” she said. “Because everybody who can afford an association and a lobbyist would have been hammering the legislators this coming session for exemptions.”
Hancock said lawmakers could have removed some of those vulnerabilities when drafting the measure.
“If there had been a more explicit description of what is and what is not going to be subject to sales tax, I don’t think that would have made the difference, but it would have been helpful,” Hancock said.
The campaign also carried the political baggage of a decades-long push by some of Missouri’s wealthiest conservative donors to eliminate the income tax.
The most prominent backer of eliminating the state income tax has been the No. 1 donor to Missouri Republicans over the past two decades. Rex Sinquefield has made $78.6 million in political donations reported to the Missouri Ethics Commission since 2006, mostly to Republicans but also to fund ballot measures he initiated.
In 2012, Sinquefield tried, but failed, to get a variation of the ideas embodied in Amendment 5 on the ballot. During this year’s campaign, he donated $300,000 to We the People Priorities PAC, which campaigned for and against individual Republicans in primaries based on whether they supported or opposed Amendment 5.
Democrats seized on that history to argue Amendment 5 reflected donor priorities more than voter priorities.
“The common theme of both those ballot initiatives were that it was the Republican Party trying to get the people to go along with their big donors’ ideas rather than them trying to deliver things that people actually want,” Webber said.
Political aftermath
For Republicans, the question now is whether voters who overwhelmingly rejected the amendments will hold lawmakers accountable for putting them on the ballot.
Riley doubts they will.
“It was what was able to pass and gave us a chance to put the question in front of the voters, and they said no, and that’s okay, and that’s fair,” Riley said. “I suspect by the time we get to November, Missourians will continue to elect Republicans across the state.”
Democrats, however, see the results as the opening they have long sought. Republicans have controlled the legislature for more than 25 years and the governor’s office for 14 of the last 22 years.
“A kind of seismic shift happened,” said Russ Carnahan, chairman of the Missouri Democratic Party.
Carnahan said Democrats will use Amendment 4 to argue Republicans tried to diminish voters’ power over the constitution and Amendment 5 to argue lawmakers prioritized ideas pushed by major donors.
“Amendment 4 and Amendment 5 will be used as symptoms of the problem,” Carnahan said. “The folks responsible for this are the Republican politicians in Jefferson City. Clearly, they’re not listening, and so it really opens a door of opportunity for us. We have to take it. We have to build those connections, but we’ve also got voters that are open to this message.”
Whether that message can move enough voters to change the makeup of the legislature will be tested in a relatively small number of competitive districts.
State Rep. Betsy Fogle, a Springfield Democrat, is seeking a seat in the state Senate in the 30th District. If she defeats state Rep. Melanie Stinnett, a Springfield Republican, she will flip a Republican-held district.
Only one other state Senate district, in the 8th District in Jackson County, is viewed as a potential party change, also from Republican to Democratic.
Tuesday’s results, Fogle said, give Democrats an opening with voters frustrated by one-party control.
“Voters are frustrated with one party having so much power that they put something on the ballot that was so unpopular with the electorate,” she said, “something that was going to give unchecked power to the General Assembly to increase taxes on any good and service.”
What Tuesday’s primary results say about Amendment 5 and the next Missouri Senate
Fogle pointed to Rook’s upset win over Trent, the Senate sponsor of Amendment 5. Rook also publicly opposed Amendment 4.
“Lori Rook demonstrated that she was on the right side of two very important issues to voters, and I think that I imagine that played a significant role in the defeat of an incumbent,” she said.
Democratic enthusiasm was clear in Tuesday’s turnout. The 1.4 million voters continued the trend of past primaries where high-interest ballot measures bring out a larger, more Democratic electorate.
Nearly 520,000 Democratic ballots were cast in congressional primaries Tuesday, compared to 380,000 in the 2024 primary for governor and 370,000 in the 2022 primary for U.S. Senate.
But whether those extra Democratic voters will show up in November is unknown.
This year also offers few obvious historical comparisons. A likely uncompetitive statewide race for auditor will share the November ballot with at least one intensely contested constitutional amendment — Amendment 3, which would make most abortions illegal. The ballot could also include a referendum on Missouri’s new congressional map and a constitutional amendment limiting lawmakers’ ability to change laws approved by voters.
Carnahan said ballot measures will be the main draw statewide this year and turnout will be strong and receptive to the party’s message.
“Republicans control every level of state government and have for a couple of decades, and they own these bad ideas that went down in flames,” Carnahan said.
But Tuesday’s results also complicate any simple partisan explanation of what Missouri voters want.
On the same ballot where just 16.6% supported Amendment 5, roughly 83% backed Amendment 1, which extended for another decade a statewide sales tax dedicated to parks and soil conservation.
Fogle said the nearly mirror-image results show voters were not simply rejecting taxes.
“If you show voters the value in what you’re asking them to pay for, they are going to make the right decision,” she said.
The results show voters are persuadable everywhere, Fogle said, and ready to listen.
“You saw that voters can have nuanced opinions,” she said, “and if given the information, can make a decision that they think is best for the future of our state.”