But the former House speaker on Sunday attracted an overflow crowd in central Florida, where he sharpened his attack on Romney.
"I believe the Republican party will not nominate a pro-abortion, pro-gun control, pro-tax increase moderate from Massachusetts," Gingrich said. "I think they will not nominate somebody who raises millions from Wall Street to run ads that are false."
Romney rallied his supporters in Naples. The former Massachusetts governor says Gingrich has failed to connect with Florida voters.
"He was on TV this morning going from station to station complaining about what he thinks were the reasons he's had difficulty here in Florida," Romney said.
Romney and a pro-Romney super PAC are outspending Gingrich 4 to 1 on TV ads in Florida. Ads for Romney have so far totaled $13.8 million, compared to ads for Gingrich at $3.8 million.
One ad that attacks Gingrich aired less than 48 hours after he won the South Carolina primary.
Romney is feeling upbeat that Florida will follow New Hampshire's lead. He says his rival is straying from the issues that matter to voters.
Nevada's largest newspaper announced Sunday it is endorsing Romney. He's already advertising in the Silver State.
Rick Santorum and Ron Paul are investing little time and money in Florida. They trail Gingrich and Romney in the polls by a wide margin.