Former West Virginia state delegate Pat McGeehan has entered the GOP primary in the state's open Senate race, depriving Rep. Shelley Moore Capito of an unobstructed path to the GOP nomination.

McGeehan, an Air Force Academy graduate and former intelligence officer who has served in Afghanistan according to his bio, announced his bid in a tweet and on a local radio show Tuesday morning.

It's not clear whether McGeehan will pose a real threat to Capito. He was elected to the state House of Delegates in 2008 but lost a pair of state Senate races in 2010 and 2012, failing to win his party's nomination the first time around.

Capito has emerged as the clear favorite to win the GOP nomination and has yet to draw a major Democratic opponent. But some conservatives, particularly the Club for Growth, have been seeking out an alternative in the primary.

The Club said Tuesday that the group has not met with McGeehan.

Sen. Jay Rockefeller (D-W.Va.) is retiring, and Republicans are favored to win the seat. Potential Democratic candidates include attorney Nick Preservati, Secretary of State Natalie Tennant, former state party chairman Mike Callaghan and attorney Ralph Baxter.

Update 5:05 p.m.: Club for Growth head Chris Chocola has invited McGeehan to sit down with the group: