This November, the Oregon voters who receive ballots will look different from the electorate of decades past: Unaffiliated and minor-party voters will outnumber Democrats.

The state hit that milestone last September—and it happened in large part thanks to Oregon's motor voter registration, which defaults to registering as unaffiliated anyone who comes through the state's Driver and Motor Vehicle Services division. This week, John Horvick, political director of DHM Research, compiled state elections statistics to show the trend lines.

It's not yet clear what impact this will have on elections in Oregon, where the governor's mansion and both houses of the Legislature are controlled by Democrats. Republicans and Democrats turn out to vote in larger numbers than unaffiliated voters, notes Horvick. Here's the longer-term trend of Oregon's party registration.