Smith, the speaker pro tem of the state house, won after a few rounds of voting by the local Republican Party. Former Senate candidate and state treasurer Sarah Steelman (R), who'd been running for the seat, dropped out on Friday before the local party voted. Missouri Lt. Gov. Peter Kinder (R), who'd also been interested in the seat, dropped out before the voting began.

The official election will be held in June, but Smith is all but guaranteed to win the House seat as the GOP nominee. The district has been in Republican hands for more than three decades and gave President Obama just 32 percent of its vote last election.

Emerson resigned from Congress in late January take over the National Rural Electric Cooperative Association.