The race to replace Sen. Sam Brownback (R) isn’t the only rough-and-tumble Republican primary in Kansas.

As Reps. Todd Tiahrt and Jerry Moran battle over the Senate opening, the open-seat primaries in their districts have heated up as well. A tight Republican primary in Tiahrt’s district has become particularly ugly, with frontrunners Wink Hartman and Mike Pompeo trading accusations for months.

The opening salvo was a “clean campaign” pledge businessman Hartman signed and sent to Pompeo in May. When Pompeo, a Republican national committeeman, refused to sign, offering an alternative pledge for Hartman to sign, Hartman aired an ad showing his pledge without Pompeo’s signature.

That was only the beginning. Pompeo noted that Hartman was registered to vote in Florida, where he owns a vacation home, from 2002 until shortly before he filed to run for Congress in Kansas. Hartman’s campaign said he registered there because he’s often in Florida when elections are held in November.

Hartman grew up in Kansas and graduated from Wichita State University, and he owns Wichita-based Hartman Oil Co. He has been painting Pompeo as a party insider, pointing to a fundraiser Pompeo held in Washington, D.C., hosted by former National Security Adviser Robert McFarlane.

Hartman’s campaign seized on an April Wichita Eagle story describing McFarlane, who was a defendant in the Iran-Contra case, as a lobbyist for Sudan. Hartman’s campaign also insists that many of nearly 100 donors whose jobs are unlisted on Pompeo’s most recent campaign finance report are lobbyists.

Candidates for federal office are required to list their donors’ professions and employers, and Pompeo said his campaign is striving to fill in the blanks.

“It’s a pretty clean report, and we’re looking to round up every single one of them,” Pompeo said in a phone interview this week. “I’m happy to report the truth about that.”

Hartman has also accused Kansas-based Thayer Aerospace, which Pompeo founded and owned partially until 2005, of shipping jobs to Mexico. Now Pompeo, an Army veteran, owns an oil and gas company in Kansas.

The race is close and tightening as the Aug. 3 primary nears. A SurveyUSA poll conducted earlier this month showed Pompeo and Hartman statistically tied with 32 percent and 31 percent, respectively. State Sen. Jean Schodorf trailed with 16 percent, small-business owner Jim Anderson got 9 percent, and businesswoman Paij Rutschman barely registered with 1 percent. The poll’s margin of error was 5.5 points. A poll conducted on July 22 by Jayhawk Consulting Services for the Schodorf campaign showed Schodorf leading with 24 percent, Pompeo with 21 percent, Hartman with 16 percent and Anderson with 7 percent. Another 32 percent of voters were undecided. The margin of error was 5 points.

Schodorf, who has served in the Kansas Senate since 2001, hopes the mudslinging will create an opening for her, as she has remained mostly above the fray. Over the weekend, she got the endorsement of the Wichita Eagle. Schodorf is a rarity for a competitive Republican primary candidate in the heartland: She supports abortion rights. Yet she and the other candidates are well behind Pompeo and Hartman in fundraising.

Schodorf has raised $64,000 throughout the course of the campaign, and she ended the second quarter with $17,000 on hand. Hartman had raised $1.4 million through June 30 and Pompeo had raised $886,000, according to their most recent Federal Election Commission reports.

Anderson’s campaign said he’s gaining ground, having raised a campaign-best $15,000 last week, and he started airing his first ads this week. Like Schodorf, he hopes to benefit from the Pompeo-Hartman showdown, but unlike Schodorf, his base is among tea party conservatives.

“Jim was in the tea party movement before it was cool and before it was demonized,” Anderson media coordinator Shanen Taylor said.

The district supported Sen. John McCain (R-Ariz.) with 58 percent in the 2008 White House election, so the Republican winner is expected to win on Nov. 2 as well. But national Democrats are high on state Rep. Raj Goyle, an accomplished fundraiser who is expected to defeat retired court services employee Robert Tillman in the primary. Goyle has been on the airwaves since July 12 and is actively campaigning around the district. His campaign manager, Kiel Brunner, noted that Democratic Rep. Dan Glickman held the seat before Tiahrt.

“It’s going to be a tough race,” Brunner conceded. “That’s why we’re out working very hard.”