GOP presidential candidate Jeb Bush said Tuesday that when voters reflect on the policy proposals from Donald Trump there's going to be a "reality check."
"Crazy talk isn't going to get us out of the mess we're in," Bush told CNBC's "Squawk Box." He said he has a "more credible message" than Trump, who's leading the Republican primary race by a wide margin, according to an aggregation of national polls.
Read More Trump: Apple should build 'their damn things' in US
"Either Trump will change his mind on these subjects, which I doubt, or he's going to pay a price," Bush said, citing as an example the recent controversy over what Trump said to The New York Times about imposing a 45 percent tax on China imports.
"Donald Trump has proposed a 45 percent tariff on all imports for China. He can deny it now, but that's what he's proposed," Bush asserted. "He's proposed in effect a global depression."
Trump said the Times got it wrong.
The paper, meanwhile, released audio of an interview with Trump that it said showed editors characterized statements by the billionaire real estate mogul correctly.
Fear mongering is not the way to fix the U.S. economy, Bush told CNBC on Tuesday. Instead, he said, the country needs reforming taxes and regulations and embracing the American energy boom. "We should be growing far closer to 4 percent than 2 percent."
Bush said his message is "beginning to be heard," with polls on the rise in the early nominating contest states of Iowa, New Hampshire and South Carolina. "We have resources to go the distance," he added.
According to the latest RealClear Politics poll aggregator, Bush was in fifth place nationally and in Iowa. He was in sixth in New Hampshire and fourth in South Carolina. Trump was leading with 34.5 percent overall. His nearest rival was Sen. Ted Cruz of Texas at 19.3 percent.
US-Iran relations
On Iran, Bush was critical of President Barack Obama's dealings with rouge nation, saying that if he were in the White House he probably wouldn't have done the prisoner exchange with Tehran.
"It may set the stage having other hostages be taken by countries that are enemies of ours," Bush said.
Bush called the overall relationship of the U.S. with Iran "flawed," saying he would not have limited the scope of international negotiations to only curtailing Iran's nuclear program. "[Obama] unilaterally conceded everything."
Read MoreHow the lifting of Iran sanctions will hit oil: Experts
The former Florida governor said he would have also insisted on addressing Iran's role in support of terrorism in the Mideast.
"We show a weakness in the way we negotiated with Iran," he continued. "The net result is our allies, like Saudi Arabia and others now, no longer think we have their back. It creates insecurity."
Economic sanctions against Iran were lifted over the weekend, after the international nuclear agency declared Tehran had fulfilled its commitment to scale back its nuclear program.
Secretary of State John Kerry over the weekend said the nuclear deal, while separate from the prisoner deal, accelerated the swap.
But while terms of the multination nuclear agreement went into effect, Obama on Sunday imposed new sanctions over Iran's ballistic missile testing.
Education reform proposal
Bush, who built a reputation for reforming Florida's public school system during his two terms as governor, told CNBC he'd like to see an expansion of the scope of the 529 college savings plans as part of his national education overhaul.
"It could be used for private schools in the K-12 system, tutoring, for a certification program so you're focused on college-readiness," he said a day after rolling out a broad education reform plan to shift power to states and local districts and away from the federal government.
Read MoreDoes Bernie Sanders actually want to be president?
Evoking the memory of the Rev. Martin Luther King Jr., on the holiday honoring the slain civil rights leader, Bush said on Monday, "Access to a quality education is the great civil rights challenge of our time."
— The Associated Press contributed to this report.