Rep. Bruce Braley clinched the Democratic nomination in the race to succeed the retiring Sen. Tom Harkin (D-Iowa), the Associated Press reports.
Braley was running unopposed in the Democratic primary.
He will face state Sen. Joni Ernst, who won her Republican primary on Tuesday, in November's general election.
In March, Braley attracted negative media attention after he made critical comments about Sen. Chuck Grassley's (R-Iowa) background as a farmer, though it appears he emerged from the scrutiny relatively unscathed.
HuffPost Pollster, which combines all publicly available polling data, shows Braley leading Ernst by five percentage points.