DFL gubernatorial hopeful Mark Dayton said Monday that GOP operatives harassed him at an outdoors expo over the weekend and prevented him from talking to Minnesota voters.

By following him at close range with inexpensive Flip cameras, Dayton said the video trackers "made it impossible for me to conduct normal campaign activities."

Republicans say that the staffers they hired to track and record Dayton were polite and that Dayton overreacted to a time-worn tactic that political parties use to keep tabs on rivals.

"When you interfere with the ability of Minnesotans to walk up to another candidate and have a civil conversation, you have gone too far," Dayton wrote in a letter to state GOP chairman Tony Sutton. "It is intentional harassment, disruption of our campaign activity and intimidation of Minnesota voters."

Dayton called on all three parties to stop using so-called candidate trackers except at public events like candidate forums and debates. He said that trackers should clearly identify which party or candidate they work for.

GOP spokesman Mark Drake said that Republican party officials won't change their use of trackers.

"I am sure Mark Dayton would like to hide from the voters for the next three months, but that's just not going to happen," Drake said. "This isn't 1982. Tracking is a routine part of politics now. ... I've never seen this sort of bizarre, weird, erratic reaction."

At a Capitol news conference on Monday, Dayton showed video his campaign recorded of two GOP trackers standing just a few feet from the former U.S. senator's booth at the Game Fair expo in Anoka. Instead of the video cameras used in previous campaigns, the trackers used smaller Flip cameras, which have a limited range and require the user to be much closer to the subject than with more expensive equipment. The video Dayton played showed the two operatives standing in the middle of a narrow path at the expo, sometimes appearing to block people walking by or make it difficult for them to talk with Dayton.

Political parties have long hired staffers to stick close to political rivals and record their every move, in hopes of capturing a contest-changing gaffe, like when former U.S. Sen. George Allen of Virginia referred to a rival's tracker as "Macaca," a derogative racial term. Sometimes the trackers become such fixtures on the campaign trail that candidates banter with them at events.

DFL Party chairman Brian Melendez said that while he's heard of no problems with GOP trackers until now, he reviewed what happened at Game Fair and said the trackers were out of line.

"Up to this date, Republicans have never gotten in a candidate's face like these kids did," Melendez said.

Baird Helgeson • 651-222-1288