It was hardly a traditional contest. The district has been historically conservative, with GOP Rep. Wayne Gilchrest controlling the seat for the past 18 years. According to Congressional Quarterly, Gilchrest also contributed to Harris’ loss:

Kratovil, who was aided by the national Democratic Party’s momentum throughout this election year, also benefitted enormously from a deep rift within Republican ranks resulting from the conservative Harris’ defeat of the more moderate Gilchrest in the district’s Feb. 12 primary.

Gilchrest and his loyalists were embittered by attacks from Harris and outside conservative groups, such as Club for Growth, that questioned his credentials as a Republican. And Kratovil soared into serious competition in early September when Gilchrest crossed party lines to endorse him to be his House successor.

The confirmed victory bumps the number of Democratic House seats next year to 255 — 20 more than the party currently controls. And that margin could grow. Five races around the country remain to be decided.