Pompeo, left, and Tiahrt, right. (AP Photo/The Wichita Eagle, Mike Hutmacher)

Kansas is suddenly a hotbed of intra-party GOP conflict. You may be familiar with the revolt of more than 100 Republican officials who chose to endorse a Democratic candidate for governor instead of the incumbent, Gov. Sam Brownback (R). That fight was the latest in a long-running feud between the state's moderate Republicans and its more conservative ones.

But that's the main event. On the undercard is the state's 4th Congressional District is a little different, where an incumbent is facing a surprisingly tough race -- against the man he replaced, and who blessed his campaign to do so.

In 2010, then-Rep. Todd Tiahrt (R-Kan.) threw his hat into the ring for the state's U.S. Senate seat (which was being vacated by Brownback). Tiahrt ran a competitive race against now-Sen. Jerry Moran, but lost.

Tiahrt gave up his seat in the 4th district when he decided to run against Moran, endorsing Mike Pompeo, who won. When Pompeo ran for reelection in 2012, Tiahrt endorsed him again. "I supported Mike’s first campaign," he said in a statement. "Since then, he has worked hard to listen to Kansans and live up to his campaign promises during his first year in office."

But now Tiahrt would like his seat back. In May, he announced that he would challenge Pompeo, saying in a statement that "our representative needs to be here listening to the people." Pompeo pointed out that this was somewhat different from what he'd said a few years earlier. "The contrast between these two statements," Pompeo said, "is exactly the kind of classic politician doublespeak that has led voters to so deeply mistrust elected officials."

The once-incumbent Tiahrt appears to be making up ground on the now-incumbent Pompeo. A poll conducted by KSNW-TV by SurveyUSA had Pompeo up by 17 about a month ago. A similar poll from KSNW, released on Wednesday, saw that lead narrow to 7 percentage points. It's important not to read too much into these polls, which are automated surveys with live calls to cell phone users and, more importantly, are about the only data points in the race. But we pontificate based on the evidence at hand, and that evidence suggests a race that's getting closer and a potential incumbent in trouble.

So far this year, only two incumbent House members have lost primaries: Reps. Eric Cantor (R-Va.) and Ralph Hall (R-Tex.).

This being Kansas, agriculture has become a key point of contention -- though not always as you might expect. In late June, a farmer noted that an ad for Pompeo used stock footage from wheat harvesting in Europe. (He knew this because the thresher pictured in the ad isn't available in the United States, as the Wichita Eagle reported.) This, Taihrt said, proved that Pompeo "is clearly out of touch."

This week, Tiahrt went a different direction on agricultural issues, accusing Pompeo of "crony capitalism" for introducing H.R. 4432. The measure would prevent states from passing individual laws mandating the labeling of genetically modified foods -- the sort of limitation that usually frustrates Democrats, not conservatives. (Tiahrt's argument is, in part, that this would create a new bureaucracy at the FDA, which does sound typically Republican.)

A position in support of GMO labeling would find wide support from the public; a 2013 60 Minutes/Vanity Fair poll found that 93 percent of Americans support labels indicating that food contains genetically modified ingredients -- including 91 percent of people in the Midwest. But those voters are probably less motivated to take action on the issue than the agricultural businesses that would rather not have to label their products accordingly.

Update: A spokesman for the Pompeo campaign points out to us that Tiahrt sponsored a similar measure in 2006 -- H. R. 4167, the "National Uniformity for Food Act." While the bill doesn't specifically mention GMOs, it similarly prevents states from enacting their own labeling standards. Tiahrt co-sponsored and voted for the bill.

The crony capitalism charge Tiahrt levels stems from Pompeo having received contributions from such businesses. Pompeo has vastly outraised Tiahrt so far, thanks in part to backing from business groups and Tiahrt's exceptionally late start. Shortly after Tiahrt announced, the Center for Responsive Politics wondered who would win the support of hometown employers Koch Industries. Tiahrt had received the company's blessing when he was in the seat; since then, Pompeo has become something of a favored son. For his 2014 race, Pompeo has received $54,000 from Koch PACs and employees. And Pompeo is the company's largest recipient.

Early voting has begun in the district for the Aug. 5 primary. For outside observers, the end result is probably a wash: A conservative Republican replacing another conservative Republican, or a conservative Republican holding a seat. (Democrat Perry Schuckman is not going to win.) But that certainly doesn't mean the race lacks for interesting details. And we feel confident in predicting: With more to come.