SALEM, Ore. (AP) – A Republican state senator in Oregon has been criticized after claiming slaves benefited from being designated as three-fifths of a person.

Sen. Dennis Linthicum said on Tuesday during floor debate that the Three-Fifths Compromise was meant to prevent slaveholding states from gaining too much power in Congress.

The comments came amid discussion over whether Oregon should switch to a national popular vote model for presidential elections.

The Three-Fifths Compromise was an agreement that came out of the 1789 Constitutional Convention. Slaves were designated as three-fifths of a person when calculating a state’s number of representatives. It gave slaveholding states more power in Congress until northern states saw a population increase.

Sen. James Manning, a Democrat from Eugene, said Linthicum’s comments rewrite history and are an “offensive mischaracterization.”