The tax that bugo is referring to is not the gas tax, but rather the tax on oil production. This tax was lowered from 7% to 2% in 2014, signed into law during the term of Gov. Mary Fallin, during a trough in oil prices which impacted the profitability of Oklahoma oil companies. The resulting loss of revenue was one of many factors leading to the education crisis a few years later. Conservatives say that the tax cut incentivizes oil production and keeps jobs in Oklahoma, while liberals and progressives point out that the oil companies can't really pick and choose where the oil is (you can't just choose to drill for oil in a lower-tax state), and they didn't just leave it in the ground when the tax rate was 7%.