Noting he'd been "energized and touched by the groundswell of encouragement," Krolicki said "now is not the proper time for a final decision to enter this race and to begin an all-consuming campaign. ... [T]here are simply too many issues of consequence being debated in the Legislature which demand all participants’ undivided attention."

Meanwhile, Lippold joins former Senate candidate Sharron Angle, who announced in March, in the primary for Heller's seat. Angle, a Christian conservative, is expected to be a formidable opponent, having run for the GOP nomination in the district before in 2006, when she lost to Heller by 421 votes.

Lippold took aim at his likely primary opponents, noting each has a long political career.

"I can't remember an election cycle in Nevada in which Sharron Angle or Brian Krolicki weren't running for something," Lippold said. "They both have some good qualities but now is not the time for habitual, serial candidates. Now is the time for new conservative leadership."

--Updated at 4:52 p.m.