The Tennessee Constitution says, “If the people shall approve and ratify such amendment (to the Tennessee Constitution) by a majority of all the citizens of the state voting for Governor, voting in their favor, such amendment shall become a part of the Constitution.”
In 2014, an amendment concerning abortion was on the ballot, placed there by the legislature. It received 729,163 yes votes and 657,192 no votes. The state government declared that it had passed. The number of votes for Governor was 1,353,728; half of that number is 676,864.
Some opponents filed a federal lawsuit, saying the measure did not pass because the state did not show that a majority of people who actually voted for Governor had voted for the amendment. In order to show this, each ballot would have needed to be re-counted, to disregard votes on the amendment from people who abstained from voting for Governor. In other words, these voters take the meaning of the Tennessee Constitution to refer to particular voters. These voters won in U.S. District Court, but in January 2018, the Sixth Circuit reversed and said the measure passed.
Here is the cert petition. A great deal of the petition focuses on the procedural issue of whether it was wrong for the state officials to have filed their own lawsuit in state court, to get a favorable ruling on their side, instead of letting the federal court handle the case. The case is George v Haslam, 18-76 (although in the lower courts it was called George v Hargett).