URBANDALE, Iowa (AP) — Iowa Republicans are gathering Saturday to pick a candidate to run in November for the seat of retiring Rep. Tom Latham in Iowa’s 3rd Congressional District. More than 500 delegates will meet at Des Moines Christian School in Urbandale to choose from the six candidates who ran in the June 3 primary but failed to reach the required 35-percent threshold.

State Sen. Brad Zaun received the most votes, ahead of businessman Robert Cramer, GOP activist Joe Granadette, Secretary of State Matt Schultz, Iowa Renewable Fuels Association Director Monte Shaw and former U.S. Senate aide David Young. It’s the first congressional nominating convention in Iowa since 2002. The winner faces Democrat Staci Appel of Ackworth in the general election.

The district includes 16 counties, stretching from Des Moines to Council Bluffs.