In May 1878, Weaver accepted the Greenback nomination for the House of Representatives in the 6th district. Although Weaver's political career up to then had been as a staunch Republican, Democrats in the 6th district thought that endorsing him was likely the only way to defeat Sampson, the incumbent Republican. Since the start of the Civil War, Democrats had been in the minority across Iowa; electoral fusion with Greenbackers represented their best chance to get their candidates into office. Hard-money Democrats objected to the idea, but some were reassured when Henry H. Trimble, a prominent Bloomfield Democrat, assured them that if elected Weaver would align with House Democrats on all issues other than the money question. Democrats declined to endorse any candidate at the 6th district convention, but soft-money leaders in the party circulated their own slate of candidates that included Democrats and Greenbackers. The Greenback–Democrat ticket prevailed, and Weaver was elected with 16,366 votes to Sampson's 14,307.