Five Highlights From the GOP Debate in Las Vegas

CNN's Republican debate on Tuesday night was predictably dominated by sparring among front-runner Donald Trump and his closest competitors: Senators Ted Cruz and Marco Rubio and former Florida governor Jeb Bush. The remaining five candidates on stage struggled to muscle in on the discussion, with Carly Fiorina and Ben Carson openly complaining about their lack of airtime. John Kasich, Chris Christie, Rand Paul ddin't even get that much time.

Amid the posturing, the pontificating and the verbal sparring, here were five highlights of the two and a half hour debate at the Venetian hotel in Las Vegas, moderated by CNN veteran Wolf Blitzer.

• If you build it, they won't come. Trump and Cruz agreed that the nation's borders would be more secure if giant walls were erected to stop illegal immigrant and drug trafficking. "Walls work, if they're properly constructed," Trump said. Cruz did him one better. "We will build a wall that works and I'll get Donald Trump to pay for it," he said.
• Donald takes the oath. The questioners pressed Trump on whether he would stick to his vow not to run as an independent candidate if he is not the eventual Republican nominee next year. Trump spoke like a front-runner with a double-digit margin: "I'm totally commmited to the Republican party. I'm honored to be the frontrunner. I will do everything in my power to beat Hillary Clinton."
• He's tough. He's nice. He's disingenuous. Trump continued to direct most of his fire toward Bush. At one point Trump called Bush a "very nice person" and then mocked him for being a "tough guy" who is far behind him in the polls. When Bush tried to talk over him -- calling it "a little of your own medicine," Trump smirked. "I know you're trying to build up your energy but it's not working."
• "Infiltrating" the Internet. Trump continued to advocate for shutting down parts of the Internet to guard against ISIS recruiting efforts. He did not elaborate on the practial reality of doing so, other than to say he would enlist the best and the brightest from Silicon Valley to out-hack the jihadis. "ISIS is using the Internet better than we are using the Internet and it was our idea," Trump said.
• A bridge too far? With New Jersey Gov. Christie on stage, it was inevitable that New Jersey's bridge-closing scandal would come up. Paul argued with Christie about the latter's assertion that the U.S. needs to get tough with the Russians on no-fly zones in Syria and elsewhere. Paul said voters had to question Christie's judgement and temperament in stressful situations. Voters had to think hard about the electing someone with a reckless approach to foreign policy - soemone "who might shut down a bridge because they don't like their friends," Paul said.