Now for the standard caveat: The annual Kansas Speaks survey by Fort Hays University was only one poll with a margin of error of 3.9 percent. And polls often show some level of voter remorse in the year after an election. In 2013, some national surveys found that Romney would have defeated Obama if voters had a do-over.

But rarely do a governor’s approval ratings tumble as dramatically as Brownback’s, and it’s a reflection of just how firmly Kansans have rejected his supply-side economic program. Working in concert with a Republican-controlled legislature, Brownback won approval for deep tax cuts both for individuals and businesses, which he claimed would lead to stronger job-creation and economic growth. But while the policy’s impact on jobs was debatable, its effect on the budget was not: Revenue projections consistently—and badly—missed their targets, and by early 2015, Brownback was forced to confront a projected deficit of $600 million. The governor blamed court-mandated increases in education spending, but he had no choice but to propose a slowing of the planned tax cuts and an increase in cigarette and other sales taxes to make up the difference. Lawmakers bickered for weeks before finally voting on a budget that, as even Brownback admitted, pleased no one.

The governor has crossed voters in other areas. The social conservative signed an executive order on “religious liberty” in July in response to the Supreme Court’s decision legalizing same-sex marriage. The poll released Sunday found that a plurality of voters supported gay marriage and a slim majority believed that business owners should have to provide the same services to gay couples as straight couples. Brownback signed a new voter-ID law in June, even though most Kansans—according to the survey—said voter fraud was no more than “a minor problem.” Yet Brownback’s tenure remains defined by his experiment with taxes. He has said repeatedly his goal is to reduce the income-tax rate to zero, but it’s possible his approval rating will get there first.

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