DES MOINES, Iowa (AP) — Ads for Republican Joni Ernst from the powerful U.S. Chamber of Commerce add to the sense of momentum for the state senator, who would be the party’s first woman nominee for U.S. Senate, should she win on June 3.

The ads also mark an uncommon alliance between conservative groups and more traditional pro-business GOP interests. Ernst also is the first U.S. Senate candidate this year to receive the support of the U.S. Chamber of Commerce and Senate Conservatives Fund. The latter has endorsed GOP primary challengers and non-establishment Republicans in high-profile Senate primaries this year in Kentucky, Mississippi, Nebraska and elsewhere.

Ernst is the only woman in a five-candidate field, and has led in recent polls. Democratic U.S. House member Bruce Braley is unopposed for his party’s nomination.