Ben Carson threatens to leave the Republican Party

Trump also has taunted the Republican Party with the possibility of mounting a third-party independent run for president - a move that would nearly certainly benefit the Democratic nominee in November by splitting the Republican vote. That would mean open floor fights, both for the nomination and on the party platform. A brokered convention takes place when no candidate wins on the first ballot. In subsequent ballots, delegates would be free to switch their votes, or even to vote for someone outside the existing field of candidates, opening up a potentially chaotic arena for political scheming and horse-trading.

Priebus and McConnell were reportedly silent as the issue was discussed, apparently to avoid being seen as anti-Trump.

Senior GOP officials met at a routine private dinner this week and discussed the possibility of a brokered Republican convention, which hasn't happened in decades.

John Kasich said he does not hear people in early voting states talking about whether to keep Muslims out of the U.S. These results must be very disquieting for the leadership of the Republican Party.

Rupert Murdoch has some words for the Republican Party - don't interfere with Trump. For now, however, the best bet for Republicans is to watch quietly and hopefully, and continue to back more mainstream candidates for the nomination. But GOP insider Ford O'Connell said Trump remains a force to be reckoned with.

On "Fox News Sunday" real estate mogul Trump lashed out at Cruz, who has taken a 10-point lead over Trump among Iowa Republicans weeks before the state's caucuses, according to a new Bloomberg Politics/Des Moines Register poll.

For months, Trump has been atop most national polls in the race for the Republican nomination.

The early caucus state has been a focus of Cruz's recent efforts.

The Reuters/Ipsos survey released Friday shows that 35 percent of Republican voters support the businessman, putting him far ahead of closest rival Ben Carson, who has the backing of just 12% of voters.

Republican National Committee spokesman Sean Spicer downplayed talk that GOP officials are considering a brokered convention - a less-scripted event during which campaigns compete for delegates - if a consensus nominee does not emerge.

But its Trump's supporters who are laughing now. Trump called Cruz "a nice guy" who would have a place in a Trump Administration.

"We're doing well with everybody", he said, noting that he's puling support from tea party activists and evangelical Christians in a state where several influential Iowa conservatives have recently endorsed opponent Sen. In the wake of terrorist attacks in Paris and San Bernardino, California, Trump modified his theme by saying he wants to "make America great and safe again".

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