!--StartFragment-->

The big news from the CNN's Republican debate in Las Vegas is that there was a knockdown, dragged-out fight going on and likely to go into the future between Marco Rubio and Ted Cruz. There's not space or time here to fact check and critique their comments, but they did present significantly different views on foreign policy and immigration which were — and should be — major issues in this nomination race. Rubio in effect confessed error for his support of the "Gang of Eight" comprehensive immigration bill in 2013; it will be interesting to see if this satisfies Republican primary voters and caucusgoers. My own instinct is that Rubio is occupying the more sustainable ground, but we'll see.

Other candidates cruised pretty comfortably in their own lane. Donald Trump was Donald Trump, sometimes interesting, sometimes brutally dismissive (of Jeb Bush's poll numbers, for example), but almost mellow in his pledge to support the winner of the Republican nomination. Jeb Bush tried to get himself back into contention, especially with his obviously prepared characterization of Trump as a "chaos candidate." But the problem here is that in a multi-candidate race, if candidate A attacks candidate B, it may hurt B, but it also tends to hurt A, and help candidates C and D and E. In this case, I think Bush's attack was enough out of line with his demeanor that this just doesn't work for him.

Chris Christie made a strong case for himself and has some hope of advancing to contender status in New Hampshire, where his intensive schedule of town hall meetings has propelled him to significant upward movement in the polls.

Read more on WashingtonExaminer.com