CNN has called off a GOP presidential debate scheduled for March 1 in Georgia after Mitt Romney and Ron Paul said they would not attend.
Rick Santorum's campaign had signaled that he was unlikely to attend as well.
Newt Gingrich and the other three Republican candidates are scheduled to debate Feb. 22 in Mesa, Ariz. Arizona and Michigan hold primaries on Feb. 28.
"Republicans want a candidate willing to go nine rounds with Barrack Obama, not someone who will duck and hide," said Susan Meyers, southeast communications director for Newt 2012 told Channel 2 political reporter Lori Geary.
"It's why all along it has been Newt and will be Newt for the GOP nomination. Voters are counting down the days to when Newt can take the podium to debate the president. There may not be enough electricity in America to power every TV set that will be on when that debate happens."
Romney's campaign noted Thursday that its candidate already has been in 20 debates.