I support open primaries partially based on personal experience.

I've been a liberal all my life. But I didn't think of myself as a Democrat until I was over 30 and experienced the horror of George W. Bush's presidency.

Most people under 30 don't think of themselves as Democrats or Republicans. But they have most of the same political positions now as they will when they're older.

Regarding liberals who from age 18-30 don't think of themselves as Democratic Party members and from age 31-80 do: I want them to be able to vote in Democratic primaries at both stages of their lives. They're being liberals is what is important.

22 states have no party registration. Minnesota is one of them. In US Senate primaries here, everyone gets the same ballot. There is a box with the Democratic candidates and a box with the Republican candidates, and voters can choose a candidate in either box but not both.

That's a good system because it's simple and encourages voting.