Colorado state Sen. Owen Hill (R) is dropping his Senate bid, clearing the path for Rep. Cory Gardner (R-Colo.) to face Sen. Mark Udall (D-Colo.) in November.
The move clears the way for Gardner to be the GOP nominee against Udall, who polls show is vulnerable heading into his first reelection.
Gardner is considered a top-tier candidate. He decided to run in late February after saying last year that he wouldn't challenge Udall, giving Republicans a much better shot at the race after none of those who'd already been running had caught fire.
Former Senate nominee Ken Buck (R) and Colorado state Rep. Amy Stephens (R) quickly dropped out and endorsed Gardner, but Hill, who had the backing of Tea Party Express, initially had refused to budge.
"In recent weeks, it has become clear that in order for Republicans to defeat our failed Democrat Senator Mark Udall, we must avoid a contentious primary election, in order to emerge with a nominee that is not bruised and battered heading into the General election in November," Hill said, explaining his change of heart. "This is a mistake repeated year after year in Colorado and one I won't allow to be repeated again."
The move means Gardner is all but guaranteed the nomination and will be able to save resources and position himself for the general election rather than have to worry about a challenger to his right.
This post was updated at 1:25 p.m.