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Americans thinking of moving to Canada if Donald Trump becomes U.S. President should perhaps think again. The other Republican candidates could be even scarier, a top asset manager told CNBC on Friday.

Paul Gambles, the managing director of MBMG Group, told CNBC that Trump had no foreign policy — and as such, posed less international danger than fellow Republican contenders Marco Rubio or Ted Cruz.

"I have been more appalled by Donald Trump than just about anybody, I think, but when I started to look at the consequences of him getting the Republican nomination, you know what, the others look even worse … The good thing about Donald Trump is, because he doesn't have a foreign policy, he is probably a lot less dangerous than either Rubio or Cruz put together," he said.

On his political website, Trump outlines proposed reforms for immigration and U.S.-China trade — both of which touch on foreign policy.

Republican presidential candidates, Donald Trump and Ted Cruz, participate in a debate sponsored by Fox News on March 3, 2016.
Chip Somodevilla | Getty Images

On Thursday, the tycoon-turned politician told CNBC that Beijing was "the grandmaster of all" when it came to free trade cheating and currency manipulation.

In addition, Trump has expressed support for Russian airstrikes on Syria and been generally critical of U.S. policy in the Middle East.

However, Gambles said on Friday that one of Trump's best-know policy ideas — building a wall on the U.S.-Mexico border to keep would-be immigrants out — originally came from Cruz, although both politicians claim it as their own.

"You know who first came up with the idea of building a wall between America and Mexico — Cruz. It was Cruz's policy in 2012 and all of a sudden that seems to have disappeared," Gambles.

Critics of Trump's foreign policy ideas include Republican national security leaders, who published an open letter in March saying that a Trump presidency would make the U.S. less safe.

Republican presidential candidate Donald Trump speaks at a campaign rally at the Crown Center Coliseum in Fayetteville, N.C.
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"His vision of American influence and power in the world is wildly inconsistent and unmoored in principle. He swings from isolationism to military adventurism within the space of one sentence," the open letter from the group published on the War on the Rocks website said.

Others are more positive about Trump's ideas.

"Donald Trump could bring a welcome pragmatism to American foreign policy and something we have not seen in some time — prospects for genuine success," Peter Morici, economist and business professor at the University of Maryland, said in a note on Thursday.

He added that Mexico had proved uncooperative in helping stem the flow of people to the U.S. and had failed to combat endemic corruption.

"Trump can't force Mexico City to build a wall along the border, but by taxing remittances, Washington can pressure it to start cleaning up its filthy regime and genuinely cooperate in border control," Morici said.

Republican candidate Donald Trump (l) and Democratic candidate Bernie Sanders (r).
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Cruz and Rubio are the mainstream Republican candidates, along with John Kasich, but are struggling to compete with outspoken Trump.

"All these guys who are pretending to be normal are probably every bit as crazy as Trump is. At least with Trump, you know what you are dealing with: It is a psychopath on the loose, but the others are like well-polished psychopaths in suits and that terrifies me even more," Gambles concluded.

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