Topeka ? Jim Ryun appears to be trying to give himself an advantage by calling for clean campaigning as he seeks the Republican nomination in the 2nd Congressional District.

Ryun, the congressman ousted in 2006, and his GOP rival, State Treasurer Lynn Jenkins, filed for the office hours apart last week. In between, Ryun issued his call for a campaign free of the negative attacks that he said tend to alienate voters.

Such declarations – complete with a request that the rival take a public pledge – have become common early in campaigns. They often come in races that appear destined for ugliness and typically do little to alter the tone.

Jenkins shows no signs of accepting the pledge, but if she did, it could limit her campaign against Ryun. If she rejects the pledge, Ryun is almost certain to point that fact out to voters in a bid for their support.

And, by issuing his call, Ryun is making a stab at defining what constitutes a dirty campaign. Voters expect candidates to provide some information about their opponents, but each faces the question of how many unflattering photos and sneering voice-overs they’ll put up with.

“Voters care about campaigns that cross the line,” said Bob Beatty, a Washburn University political scientist. “The biggest problem is trying to figure out where that line is, because it changes every election and with every race.”

Ryun contends he simply wants a positive campaign in which he and Jenkins discuss where they stand on the issues. His proposal is that he and Jenkins refrain from mentioning each other by name in ads and speeches.

“Republicans across Kansas are tired of divisive politics,” Ryun told reporters in a teleconference last week.

Jenkins was skeptical. She noted that last year, she was the target of ads by national groups, describing them as “buddies” of Ryun’s. Ryun’s campaign has said there was no coordination.

And, suggesting she wouldn’t take the pledge, she said: “Unfortunately, everybody knows that Jim Ryun didn’t do a lot for us in Washington, D.C.”

Republicans often bemoan contentious primaries that leave the eventual nominee battered – and sometimes penniless – going into a general election campaign.

And candidates of all stripes portray voters as yearning for a yesterday when campaigns were about discussing serious issues, not personal attacks.