Kristen Gillibrand is the Democratic candidate. Not sure it matters which row they vote for her on. She won either way.

I am familiar enough with the DFL to know they function as the Democratic Party in their state and aren't exactly the same as a third party (hard to be a spoiler when your candidates are the de facto Democratic candidates).

If people who are disillusioned with the two party system want to take over their preferred party in their state and call it something else, more power to them.