By Arun Kumar 

Washington, Dec 16 (IANS): Republican presidential candidates joined issue with frontrunner Donald Trump's call to ban Muslims from coming to the US with Senator Ted Cruz citing the example of India to say all Muslims were not jihadists.

"I understand why Donald made that proposal. I introduced legislation in the Senate that I believe is more narrowly focused at the actual threat, which is radical Islamic terrorism," he said participating in the final Republican debate of 2015 on Tuesday night.

In the debate hosted by CNN in Las Vegas, Trump defended his call, saying: ""We are not talking about isolation; we are talking about security."

"As far as other people, like in the migration where they're going, tens of thousands of people having cell phones with ISIS flags on them," he said.

"And if I'm president and if Obama has brought some to this country, they are leaving. They're going. They're gone."

Asked about his earlier comments calling Trump "unhinged," former Florida Governor Jeb Bush said: "Donald, you know, is great at the one-liners."

"But he's a chaos candidate. And he'd be a chaos president. He would not be the commander-in-chief we need to keep our country safe," he declared.

Trump was quick to hit back, saying: "Jeb doesn't really believe I'm unhinged. He said that very simply because he has failed in this campaign. It's been a total disaster. Nobody cares. And, frankly, I'm the most solid person up here."

Like Cruz, Senator Marco Rubio too declined to attack Trump outright and said: "We must deal with this threat of radical Islamists, especially from ISIS."

With the debate focussing on national security and the fight against Islamic extremism, former neurosurgeon Ben Carson declared: "We are at war."

Trump also reiterated his strategy to cut off ISIS' recruiting methods on social media, which he argued would involve collaboration with Silicon Valley and limiting Internet access.

"I would certainly be open to closing areas where we are at war with somebody," Trump said. "I sure as hell don't want to let people that want to kill us and kill our nation use our Internet. Yes, sir. I am."

Trump's suggestion prompted Kentucky Senator Rand Paul to "go back to another question. Which is, is Donald Trump a serious candidate?"

"The reason I ask this is, if you are going to close the Internet, realize America what that entails. That entails getting rid of the First Amendment. Okay. No small feat."

He added that some of Trump's proposals for fighting terrorism "would defy every norm that is American."

Trump dismissed his rival's attacks with a wave of his hand saying: "These are people that want to kill us, folks."

"And you're objecting to us infiltrating their conversations? I don't think so. I don't think so."

Earlier, in the undercard debate of bottom four candidates, Senator Lindsey Graham too rebuked Trump for his controversial proposal to ban Muslims.

"Donald Trump has done the one single thing you cannot do: Declare war on Islam itself. ISIL would be dancing in the streets, they just don't believe in dancing," Graham said. "This is a coup for them and to all of our Muslim friends throughout the world."

Former New York governor George Pataki too criticised Trump's proposal saying: "It is unconstitutional and it is wrong."

Senator Rick Santorum called Trump's idea "not the right proposal" and former Arkansas governor Mike Huckabee described the ban as "impractical."