"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.
"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.