The Minnesota Public Interest Research Group (MPIRG) has landed on a way to identify the serious candidates in a crowded race that doesn't involve money, polling, electoral experience or party endorsements.

It's Facebook likes.

Confronted with 35 candidates for mayor, MPIRG decided on likes as the standard to determine who would be invited to tonight's forum at the University of Minnesota. Three hundred likes on a campaign website prompted an invitation; eight had that many and will participate. They are (in alphabetical order) Mark Andrew, Jackie Cherryhomes, Bob Fine, Betsy Hodges, Doug Mann, Don Samuels, Cam Winton and Stephanie Woodruff.

The popularity of social media with students makes likes a valid measure of a campaign's strength, at least on campus, said Sarah Casper, lead MPIRG organizer at the U's Minneapolis campus.

Why 300?

"We just kind of cut it off there," she said. "Anything less than that is sort of irrelevant."

The forum will open at Coffman Theater with a meet-and-greet at 7 p.m., with a question-and-answer session following from 8 p.m. to 9:30 p.m.