"Primary electorates are so small it essentially encourages the Akin-ization of the entire Republican primary," Cecil said.
His reference was to Missouri 2012. Republicans were certain they could defeat Sen. Claire McCaskill, D-Mo., but their nominee, Rep. Todd Akin, flamed out after saying women's bodies can avoid pregnancy in cases of "legitimate rape." McCaskill won re-election by 16 percentage points.
Georgia rules set the primary for May 20, but if no candidate gets 50 percent, a runoff occurs July 22.
Several Republicans insist that establishment candidates will eventually prevail and the internal fights won't matter as Democrats struggle with the most contentious issue of the year — Obama's health care law — and the political damage from its many problems.
"I think it may be the most difficult political yoke to carry in the history of American politics," said Sen. Johnny Isakson, R-Ga. "Where else do you have something that affects everybody? And health care does."
Democrats don't dispute that the troubled rollout of the health care website has hurt them.
"There's no doubt Republicans are a little more gleeful," said John Anzalone, a Democratic pollster and adviser to North Carolina Democratic Sen. Kay Hagan, who is seeking a second term. "Who can say with a straight face that this has not been a bad month for Democrats?"
But Anzalone added: "It's not a permanent thing. This is really about the political environment nationally. It evens out."
In the North Carolina race, Senate Republicans have been raising money for Thom Tillis, speaker of the state House. Tillis faces challenges from Greg Brannon, a physician who has the backing of Sen. Rand Paul, R-Ky., and has been seeking the support of the tea party and Rev. Mark Harris, a Baptist minister who was instrumental in the state fight to ban gay marriage.