Okay let's assess all seven of the candidates on the stage last night one-by-one.

However, I want to start with this ridiculous Ted Cruz "born-in-Canada" business.

Why are we wasting time on this? 

Senator Cruz is an American citizen and he is entitled to run for president.

That's it.  It doesn't matter what some Harvard lawyer says.  It doesn't matter what his political opponents say.  Cruz is eligible to run.

So I'm not going to spend any time on that at all.

As to the debate, I felt sorry for Ben Carson last night.  In the first hour we saw him twice.

In fact the doctor spoke for only eight minutes and 26 seconds last night compared to almost 18 minutes for Ted Cruz.

It is simply impossible for Ben Carson to compete under those circumstances, and I think you will see his position in the polls not improve very much.

Dr. Carson is a good man, has run a dignified campaign but he is not going to win.

Jeb Bush had his best debate.  He was strong on foreign policy and did not back down from Donald Trump.

In fact when Trump attacked the governor, the crowd didn't like it.

DONALD TRUMP: “And we don't need a weak person being president of the United States, okay?  Because that's what we'd get if it were Jeb -- I tell you what, we don't need that.”

AUDIENCE: “Boo!”

TRUMP: “We don't need that.” 

Jeb Bush spoke for 12-and-a-half minutes last night and helped himself.

How much, I don't know.  The governor will hang in there and hope lightning strikes something because he needs divine intervention.

John Kasich got as much air time as Mr. Bush, and again, Kasich has been a terrific governor in Ohio.

But his record is simply not enough in this age of anger.

The governor does not reflect the mood of Republican voters.  He prefers to be a policy guy when the folks want emotion and confrontation.

In another time Kasich might have carried the day.  He will not this year.

Governor Chris Christie was his usual feisty self, and I believe he is a very strong contender for vice president.

Christie is competing well in New Hampshire, but does not seem to have enough organization and money to defeat the frontrunners.

He is, however, very effective in attacking Hillary Clinton.

CHRISTIE: “If you're worried about the world being on fire, you're worried about how we're going to use our military, you're worried about strengthening our military and you're worried most of all about keeping your homes and your families safe and secure, you cannot give Hillary Clinton a third term of Barack Obama's leadership.  I will not do that.  If I'm the nominee, she won't get within 10 miles of the White House.”

So I will not be surprised if Chris Christie gets the VP nod on the Republican ticket.  Obviously, the GOP needs votes from the Northeast.

That leaves us with the three main contenders: Trump, Cruz and Rubio.

Let's take Rubio first.  He is an excellent debater and that was on display last night. 

He flayed Ted Cruz on his voting record:

RUBIO: “You used to support TPA, now you say you're against it.  I saw you on the Senate floor flip your vote on crop insurance because they told you it would help you in Iowa, and last week, we all saw you flip your vote on ethanol in Iowa for the same reason. (APPLAUSE)  That is not consistent conservatism.  That is political calculation.” 

Cruz, of course, hammered Rubio for being a soft guy on illegal immigration.  That back and forth was entertaining.

They also went after each other on taxes.

Marco Rubio has a legitimate chance to win the nomination and is feared by the Clinton campaign.

He is articulate.  His demographic profile works, and he makes Hillary Clinton look older.

But whether Rubio can convince hardcore conservative Americans to back him remains to be seen.

The senator will be with us in just a few moments.

Ted Cruz is also a very strong debater, but got in trouble challenging Donald Trump on New York values:

CRUZ: “You know, I think most people know exactly what New York values are.  ((EDIT)) But everyone understands that the values in New York City are socially liberal or pro-abortion or pro- gay-marriage, focus around money and the media. ((EDIT)) Not a lot of conservatives come out of Manhattan.  I'm just saying.”

((EDIT))

TRUMP: “When the World Trade Center came down, I saw something that no place on Earth could have handled more beautifully, more humanely than New York. ((EDIT)) And everybody in the world watched and everybody in the world loved New York and loved New Yorkers.  And I have to tell you, that was a very insulting statement that Ted made.”

Trump won that exchange but Cruz won the Canada-birth issue, so it was pretty much a draw.

Ted Cruz had the most speaking time last night -- nearly 18 minutes.  Donald Trump was right behind him at 17 minutes, 15 seconds.

Mr. Trump did not back away from his tough anti-immigration stance concerning Mexicans and Muslims.

He also hammered China, but was a bit vague on the tariff issue. 

But as we all know, it is all about demeanor for Donald Trump, not policy.

He continues to lead in the polls because he is perceived as an avenger, a person who will knock down the political establishment.

That's what many Republican voters want this time around, and Trump delivered that again last night.

Trump has also set the agenda on immigration.

He continues to support a temporary ban on all Muslims entering America, including Syrian refugees.

In deference to that stance, all the other GOP candidates except Senator Rubio said they would prevent any person from Syria from coming here until better background checks could be developed.

Rubio was a bit more nuanced, and I will ask him about that coming up.

So, one more debate here on the Fox News Channel before the Iowa vote on February 1st.

The race is still fluid, anything could happen.

However, realistically it looks like Trump, Cruz and Rubio are best positioned to secure the nomination.

And that's the memo.