Republican voters in Iowa’s third congressional district failed to push a candidate across the 35 percent mark needed to secure the GOP nomination, so a convention will be held to pick the party’s candidate for November. Brad Zaun, a former Urbandale mayor and a current member of the state senate, was the top vote-getter, with just under 25 percent support in the primary

“My message is not going to change,” Zaun told Radio Iowa late Tuesday evening. “Obviously going to be having a lot of conversations with all the delegates. I’ve already contacted all of them once. I personally called all of them, I’m guessing probably it’s been a couple of months ago.”

Robert Cramer, a construction company executive from Johnston, was just 3.5 percentage points behind Zaun.

“We knew it would be tough to really pull away from the pack,” Cramer told Radio Iowa. “But we feel like being our first time out and not being a politician that we ran a really good campaign, had a lot of good volunteers going a lot of work and we’re really pleased where we’re ending up that we think we can now make a good case to the delegates that we’d be the right guy for the job.”

The third place finisher, with just over 20 percent of the vote, was Matt Schultz, a former Council Bluffs city councilman who is currently serving as Iowa’s secretary of state.

) “We always thought this would go to convention,” Schultz told Radio Iowa. “We’ve been preparing a convention strategy and now we’re going to execute it. My campaign’s always been about grassroots and I feel like a nominating convention is a great place for me.”

Six candidates rushed to run in the district after Republican Congressman Tom Latham’s surprise announcement in December that he would not seek reelection. Iowa Renewable Fuels Association executive director Monte Shaw finished in fourth place, with nearly 17 percent of Tuesday’s primary vote, followed by David Young, a former aide to Senator Grassley, who finished in fifth with 15.6 percent. The other candidate, Des Moines physical education teacher Joe Grandanette, finished with just 666 votes.

Iowa is one of just 11 states that require a candidate to secure 35 percent of the vote in a primary to become their party’s General Election nominee. Iowa Republican Party leaders have not set the date or location where party delegates in the third district will select a congressional nominee. A nominating convention is a rarity in Iowa politics. The last time it happened was in 2002, when Republicans chose Steve King as their congressional candidate in Iowa’s old fifth district. King had finished first in a four-way primary with just under 30 percent of the vote.