Kelliher supporters are upbeat, in large part because the House speaker appears to be holding onto a 14-point margin over Dayton.

"It's very positive," said state Rep. Frank Hornstein of Minneapolis. "We don't know where these returns are coming from, but in the last two weeks I've felt the momentum shift" for Kelliher.

Rep. Ryan Winkler, who represents Golden Valley and St. Louis Park, was cautiously optimistic. But the margin so far, he said, shows "the problem of polling in a primary race."