"A president should never talk the way he does. A president should never denigrate people the way he does. If he has turned a new leaf, it would be wonderful," Bush told CNN in an interview Saturday morning while taking his four young grandchildren to Tommy's Ham House here.
Fresh off of his New Hampshire victory, Trump has been taking fewer shots at his rivals -- except for Bush, his favorite candidate to mock -- and pulled from the air a negative ad against Ted Cruz in South Carolina. Trump lately has been trying to frame his presidential bid as one of "great optimism."
Asked if he believes Trump's new spin, Bush chuckled.
"No, I don't," he said. "But let's see ... he's winning, so maybe now that he thinks he's winning, he can change who he is. He said he has the ability to change into anything he wants. We want a president who is consistent, whose compass points north, doesn't change when it suits them, need someone who is consistent in their views and life."
His comments come just hours before the two take the debate stage along with four other Republican candidates in Greenville, one week before South Carolina's heated primary.
Bush said part of his debate strategy includes trying "to butt in when I have a chance, when I have something to say that's important" and remember that he's addressing an audience of millions rather than just the crowd that's before him.
In the last GOP showdown, Bush and Trump tangled over eminent domain, and Trump got boos from the crowd when he tried to shush the former Florida governor.
Campaigning across South Carolina this week, voters have advised Bush to be even more aggressive on stage, especially against Trump. Bush has repeatedly pounded the real estate titan in his stump speeches this week, keeping his focus more on Trump than any other rival and trying to paint the front-runner as un-presidential and unelectable.
At a town hall in Fountain Inn, South Carolina, Saturday morning, Bush invoked his opponent in an answer about Russian President Vladimir Putin.
"Putin's a bully. I'm learning about bullies now," he said to laughs. "I'm doing my own personal research on bullies, and what I believe about bullies is if you confront them and you're clear and consistent, they won't bully."
Drawing a contrast with Kasich
Saturday night's debate will be critical with a still-fluid race that has seen two different winners of the Iowa caucuses and New Hampshire primary. John Kasich is seeing a new wave of attention following his strong second place finish in New Hampshire, and Bush has been asked at least twice by voters this week at town halls to differentiate himself from the Ohio governor.
Bush has consistently pointed to Ohio's expansion of Medicaid while saying he lobbied the Florida legislature as a private citizen against the expansion. Kasich, in turn, cited Bush's position on the board of Tenet, a health care company that benefited from Obamacare.
"Well, look. He served on the board of the company that was an enthusiastic supporter of Obamacare, where I think he got like around $3 million," Kasich said on Fox News. "So don't say you were fighting it like crazy. (You) should have resigned the board if that was your point."
Bush was reportedly
paid $2.3 million in pay and stock for sitting on Tenet's board for seven years. When Bush released 33 years of tax returns
last summer, they showed that Bush made a little more than half a million dollars when he sold $1.1 million worth of company stock in 2013.
Responding to Kasich's charges, Bush told CNN he didn't "profit" from the job.
"I served on a hospital board that has 55 hospitals around the country. I did my duty well and I made it clear that I was opposed to Obamacare and that it didn't serve the best views of the country. I didn't profit off of it," he said. "John's problem is that he embraced Obamacare, thought it was right for Ohio ... he was proud of it before, not sure why he is so defensive of it now."
The two men will have a chance to contrast their records Saturday night, but until then, Bush said he has plans with his grandchildren.
"We'll spend this afternoon just chilling out. I think everyone realizes these debates can get a little tense," he said. As he held his 4-year-old granddaughter, Georgia, in his arms, he said the best thing he can do ahead of time is to "hang out with the four little munchkins I love."