[Correction: An earlier version of this article stated that nothing else was on the ballot with SQ 640. It shared the ballot with the Presidential primary election in 1992.]

In March 1992, Oklahoma voters approved State Question 640. It passed by a margin of 56 percent to 44 percent, but there was very low turnout.

The total number of voters was less than one-third (32 percent) of registered voters in the state, and it was less than half (48 percent) of the number of voters who would turn out later that year for the Presidential election. For example, President Bill Clinton, who received just 34 percent of the vote in Oklahoma in 1992, still had nearly 100,000 more votes than State Question 640.

Nevertheless, the minority of Oklahoma voters who supported SQ 640 on that day has had a dramatic and long-lasting impact on our state.

How did SQ 640 get on the ballot?

The history of State Question 640 is deeply intertwined with Oklahoma’s debates over education funding. In 1990, a bipartisan majority of Oklahoma legislators and Republican Governor Henry Bellmon approved HB 1017, the historic education reforms that paired tax increases with new requirements to reduce class sizes, increase teacher pay, strengthen teacher accreditation, and make other improvements to schools. Immediately after HB 1017 passed, a political action committee called the “Oklahoma Taxpayers Union” organized a ballot initiative (SQ 639) to repeal it. SQ 639 was voted down in October 1991, but the Oklahoma Taxpayers Union regrouped to put SQ 640 on the ballot and get it approved just five months later.

The largest financial supporter of the campaign for SQ 640 was the Oklahoma Publishing Company, the parent company of The Oklahoman newspaper. Nearly 1 out of 6 dollars contributed to pro-SQ 640 groups came from Opubco or its executives Edward L. Gaylord and Clayton Bennett (now chairman of the OKC Thunder).

On the other side, the biggest financial contributors against SQ 640 were the Tulsa Chamber of Commerce and the State Chamber of Commerce, alongside groups representing teachers and public employees.

How do SQ 640’s restrictions compare to other states?

Oklahoma’s 75 percent supermajority restriction for any tax increase is the most stringent in the U.S. Fourteen other states have a supermajority requirement to pass a tax increase:

  • A 60 percent supermajority is required in Delaware, Kentucky, Mississippi, and Oregon.
  • A two-thirds supermajority is required in Arizona, California, Louisiana, Missouri, Nevada, South Dakota, and Wisconsin. (Washington state’s supermajority law was struck down by the state Supreme Court in 2013.)
  • A 75 percent supermajority is required to raise taxes in Arkansas, but sales and alcohol tax can be increased with a simple majority. In Michigan, the 75 percent requirement applies only to property taxes.
  • That leaves Oklahoma as the only state in the country to require 75 percent supermajority approval of all tax increases.

What’s happened since the passage of SQ 640?

Since the SQ 640 required a 75 percent supermajority for any tax increase to be approved by the Legislature, lawmakers have not once cleared that hurdle. In most cases, the idea of raising taxes was not even brought up, because lawmakers knew that it would be nearly impossible.

Of course, that hasn’t prevented lawmakers from cutting taxes multiple times with a simple majority, especially in years when the economy was booming and it felt like Oklahoma had revenue to spare. As a result, Oklahomans as a whole are paying a historically low percentage of income in state and local taxes. The 7.9 percent of personal income that Oklahomans contributed to state and local taxes in 2014 was lower than all but two states and significantly below all of our surrounding states.

The cost of this disinvestment in our state has been well-documented, including the largest cuts to school funding in the nation, serious threats to the care of Oklahoma’s most vulnerable seniors and people with disabilities, tens of thousands of Oklahomans losing needed mental health care, and a prison system at the brink of collapse.

Now, majorities of Republicans and Democrats alike have realized the mistakes of the past and are acknowledging that Oklahoma has a revenue problem. But SQ 640 has allowed a minority of anti-tax legislators can still prevent the revenue solutions that Oklahomans want. Even though a revenue plan won strong bipartisan support in special session, passing the Senate with votes from 85 percent of the chamber, it fell just short in the House of Representatives with “only” 70 percent approval.

As the Tulsa World recently wrote, the Oklahoma Legislature “has become an example of the tyranny of the extremes.” To get out of this mess and make Oklahoma governable again, it’s clear that we need to undo SQ 640.