WASHINGTON – Twice burned, Republicans are treading carefully around tea party groups as they pursue a Senate majority that slipped through their fingers in 2010 and 2012.

“You’d have to be an idiot not to prepare” for primary election challenges from the right, no matter the state, said Rob Jesmer, who was executive director of the GOP Senate campaign committee when flawed, conservative candidates captured primaries, only to lose winnable races in the fall.

While incumbents work to ward off or repel challenges from within their party, a Republican tempest already is flaring in Georgia, where GOP Sen. Saxby Chambliss is stepping down. Party officials also look apprehensively toward Iowa, where Sen. Tom Harkin’s decision to retire opens up a seat long in Democratic hands.