At one of his last rallies in North Charleston, Romney arrived with more style than usual in his bus, while Gingrich, at one of his last rallies, didn't even arrive - his bus passed by outside the auditorium without slowing down.
His handlers said there were not enough people in the near-empty auditorium for a rally. They publicly called it a scheduling conflict.
Jo Anne Knatt and her husband were surprised but understanding.
"It's a disappointment, but we saw him last night," she said. "He's trying to hit as many people as he can. Romney is in the upstate today working on the evangelicals, so you gotta be where you gotta be."
On Friday night, the former Massachusetts governor was in Charleston giving his standard stump speech and singing happy birthday to South Carolina Gov. Nikki Haley, who turned 40.
"All I want is President Mitt Romney for my birthday. We've got to get him in the White House," Haley said at the rally.
Romney then launched into his attack on President Barack Obama.
"He was critical of President Bush for building a huge deficit, and then his have been three or four times as large. He was critical of the downturn in our economy, but he's been in office three years and hasn't been able to turn it around," Romney said to the crowd.
Meanwhile, Gingrich took a tour of University Children's Hospital and shook hands with doctors and staff. But he didn't answer any reporters' questions.
His wife Callista read a children's story to patients. Callista Gingrich was a staffer with whom Gingrich carried on a years-long affair while he was married to Marianne Gingrich. His ex-wife told ABC News in an exclusive interview that Gingrich asked her for an open marriage to continue the affair.
Gingrich denies it, but Marianne Gingrich said on Friday she's telling the truth.
Nearly 60 percent of the voters in South Carolina have said they are still undecided.
Former Sen. Rick Santorum and Rep. Ron Paul say they are still in the mix. Santorum says the GOP race has transformed itself in the last 24 hours
"We're going to surprise a lot of people in South Carolina here tomorrow. What we need is that good burst and surge," Santorum said.
The Associated Press contributed to this story.