2014 hasn’t been a bad year for Tea Partiers. But it hasn’t been a great one, either. Though conservatives have consolidated their electoral gains and increased their influence on the Republican Party, they haven’t picked up any notable scalps. The last hope is Kansas’s GOP Senate primary, with radiologist Milton Wolf seeking to unseat three-term incumbent Pat Roberts.

The two have had a rather unpleasant primary. Wolf tried to get Roberts thrown off the ballot after The New York Times reported that the incumbent didn’t own a house in Kansas but stayed with friends in Dodge City whenever he visited the state. Roberts supporters, for their part, made hay when it was revealed that Wolf had posted macabre patient X-rays on his personal Facebook page and made comments about them. Of a picture showing a man with his head blown off by a gunshot, Wolf wrote: “It reminds [me] of the scene from ‘Terminator 2’ when they shoot the liquid metal terminator guy in the face at close range and it kind of splits him open temporarily almost like a flower blooming. We all find beauty in different things.”

But the campaign has mostly focused on political differences. Wolf, who first came to prominence as the Tea Party leader who was a second cousin of President Obama, has run his race as an ideological purist who would model himself on Ted Cruz if elected. Wolf even sought to portray his relationship with Obama as an asset, telling The Daily Beast last year: “You cannot choose your family. But you can choose to rise up and stop your family from destroying America.”

The Tea Partier has whacked Roberts for every ideological deviation, particularly the senator’s vote to confirm Kathleen Sebelius as secretary of health and human services. Roberts had worked for Sebelius’ father-in-law, former congressman Keith Sebelius, on Capitol Hill and had a long-standing professional relationship with the former Kansas governor before her appointment to the Obama administration. But Wolf said those ties were no excuse for Roberts’ support for her nomination. Indeed, the Tea Party doctor told The Daily Beast last year that if not for Roberts’ support, Sebelius would never have been confirmed. Wolf also has campaigned as a strident opponent of Obamacare and touted his medical expertise in doing so.

Yet for all the ideological sparring, the campaign may be decided by something far less exotic: geography.

Wolf hails from the rapidly growing Kansas City suburbs, perhaps the most prosperous region of the state and one that is drawing significant economic development. (Kansas City, Kansas, was one of the first cities in the country to get Google Fiber.) By contrast, Roberts’ base, western Kansas, is a vast, sparsely populated, and heavily Republican area that still centers on agriculture. The key for Wolf is to try to cut into Roberts’ advantage in the area, which the incumbent represented in the House of Representatives for 16 years, from 1980 to 1996.

The Roberts campaign sees geography as a major issue in the race. Leroy Towns, the senator’s campaign manager, said the split in Sunflower State politics has always existed and that it’s no secret that the Wichita media market is a Roberts stronghold. Ideology, Towns added, is less important, saying he “doesn’t think anyone in Kansas has looked at this as Tea Party vs. Establishment” and scoffing at pundits who find similarities between the Roberts-Wolf race and the conservative attempt to oust Thad Cochran in Mississippi’s GOP primary. Kansas Republicans, Towns said, have long embraced conservatives, so the party establishment in Kansas is in line ideologically with “what might be the Tea Party somewhere else.”

On Wolf’s side, meanwhile, spokesman Ben Hartmann called the campaign a clear fight between insurgent conservatives and the GOP establishment. Many conservatives “feel very strongly that the establishment GOP is taking our country in the wrong direction,” he said, and are energized to support Wolf as a result. He also pointed out that Roberts has consistently avoided debating and has run a campaign the spokesman described as “based on negative advertising.” Hartmann said he was confident that his candidate would overtake the incumbent as conservatives come out to support “an outsider with a fresh perspective” over a “Washington insider.”

But while the race has tightened, it probably won’t be enough for Wolf to pull off a win. His campaign touted a poll from a pro-Wolf super PAC on election eve that had Roberts up only 9 percentage points. While that margin may hearten partisans of a candidate who was once down 50 in early polls, winning campaigns don’t often brag of being down 9 points on the night before Election Day.

The winner of the primary is likely to face Shawnee County district attorney Chad Taylor in November. Kansas last elected a Democrat to the U.S. Senate in 1932.