Mark Dayton, Tom Emmer and Tom Horner are all pledging to take the high road in the governor's race. But voters may not notice much of a difference.

There are powerful outside players in this year's election -- outside interest groups funded by labor coalitions and, for the first time, corporations that plan to spend millions of dollars on the race for governor.

Just a day after he declared victory in the DFL primary, Dayton called Thursday for an end to negative campaign ads -- including those from outside groups supporting him.

"Some people will stoop to anything, and stop at nothing, to try to destroy someone in order to defeat them," he said. "The antidote to that is for the voters to say no. I think people deserve better than that, and I'm going to give them better than that."

Republican Emmer and the Independence Party's Horner, have also pledged to keep their ads aboveboard. But two groups running ads in the governor's race weren't changing course Thursday.

Attack ads are now a staple of high-profile races and reached a peak in 2008, when the dramatic contest between Al Franken and Norm Coleman for U.S. Senate produced a steady barrage of nastiness, despite candidate calls for a cease-fire.

Alliance for a Better Minnesota, a Democrat-supporting coalition, has already spent weeks hammering at Emmer with nightly ads that cite his decades-old drunken-driving charges.

The Minnesota Republican Party announced with fanfare Wednesday that it would begin airing ads that label Dayton "erratic," for decisions he made as a U.S. senator.

State GOP officials gave no indication Thursday that they would heed the calls of any of the candidates.

Similarly, Denise Cardinal at the Alliance for a Better Minnesota said the group plans to "stay the course" on its ad strategy.

'Decent men'

Dayton on Thursday called his two rivals "decent men" and said he plans to treat them as such.

Emmer said he is "very disappointed" with anyone who would take a negative tack, including his own party's ad.

"I don't agree with that type of approach," Emmer told the Associated Press.

Legally, candidates cannot dictate what outside interest groups -- which are expected to be plentiful in the Minnesota governor's race -- do on the air and are actually prohibited from coordinating with them.

In the waning days of the 2008 U.S. Senate race, Coleman called for an end to attack ads and pulled the negative ones he'd been airing. But his allies ran their spooky music, grainy-photo ads unabated.

Horner, who has struggled to raise even a modest amount of cash and who may not have outside groups running ads on his behalf, said Thursday that he's "all in favor" of Dayton's call. Horner said he hopes to air a television ad by the end of the month.

Cardinal said that her group will continue its Emmer offensive. The alliance's current anti-Emmer ad has aired continually for nearly three weeks and is likely to be followed by more of the same.

Michael Brodkorb, deputy chair of the Republican Party, said the party wouldn't consider any changes yet.

Brodkorb said he would consider pulling the GOP ad, which accuses Dayton of being "erratic," only after it had gotten as many views as the alliance ad received. But views cost money, and it appears the Republican Party may not have the cash to spend.

Brodkorb noted that Dayton's call for positivity comes well after the alliance poured hundreds of thousands of dollars into its anti-Emmer ads.

"I think it's the absolute height of hypocrisy for Mark Dayton to stand up at a press conference and denounce ads," Brodkorb said. Why didn't Dayton make his plea when the alliance ad first appeared, Brodkorb asked.

Dayton told reporters that he didn't react to the ad initially because he wasn't yet the DFL nominee and didn't believe it was his place, not because he didn't think it was negative.

Rachel E. Stassen-Berger • 651-292-0164