'This Week' Transcript: Gov. Chris Christie, Sen. Bernie Sanders and Donald Trump

— -- THIS IS A RUSH TRANSCRIPT FOR 'THIS WEEK' ON DECEMBER 20, 2015 and it will be updated.

ANNOUNCER: Starting right now on ABC's THIS WEEK, debate night showdown -- the key moments from the final face-off of 2015.

(BEGIN VIDEO CLIP)

SEN. BERNIE SANDERS (D-VT), PRESIDENTIAL CANDIDATE: I apologize to Secretary Clinton.

DAVID MUIR, ABC NEWS CORRESPONDENT: Should corporate America love Hillary Clinton?

HILLARY CLINTON (D-NY), PRESIDENTIAL CANDIDATE: Everybody should.

SANDERS: Let's calm down a little bit, Martin.

CLINTON: Let's tell the truth, Martin.

UNIDENTIFIED MALE: Just hours after the Democrat duel, were one-on-one with the man in the line of fire.

O'MALLEY: Donald Trump.

SANDERS: Donald Trump.

CLINTON: Bringing Donald Trump back into it.

UNIDENTIFIED MALE: GOP frontrunner Donald Trump responds.

Plus, did Bernie Sanders do enough to change the race?

And New Jersey Governor Chris Christie betting it all on New Hampshire. Donald Trump, Bernie Sanders, Chris Christie, all here live, from ABC News, a special edition of THIS WEEK live from Manchester, New Hampshire.

Here now, chief anchor, George Stephanopoulos.

GEORGE STEPHANOPOULOS, HOST: Good morning from New Hampshire.

We are live from the first primary state this week, here inside the debate hall at Saint Anselm College, where the Democrats went at it last night.

It was their last debate of the year and the feistiest. The candidates clashed on taxes, gun control, the top issue right now, how to take on ISIS and protect our homeland.

Their top target, Donald Trump, attacked by name nine separate times. The only GOP candidate even mentioned last night.

Mr. Trump joins us live this morning.

Bernie Sanders and Chris Christie will be here, too.

And we begin with all of last night's big moments from our chief White House correspondent, Jonathan Karl -- good morning, Jon.

JONATHAN KARL, ABC NEWS CORRESPONDENT: Good morning, George.

Going into this debate, the Democratic race was engulfed with allegations that the Sanders campaign stole voter data from Hillary Clinton's campaign.

Bernie Sanders offered a quick apology for that before all the candidates turned their attention to their mutual enemy, Donald Trump.

(BEGIN VIDEOTAPE)

KARL (voice-over): Last night's debate started with a surprise -- a mea culpa from Bernie Sanders.

SANDERS: Not only do I apologize to Secretary Clinton, I want to apologize to my supporters. This is not the type of campaign that we run.

CLINTON: I very much appreciate that comment, Bernie. It -- we should move on, because I don't think the American people are all that interested in this.

KARL: Throughout the night, Clinton and Sanders spurred on foreign policy.

CLINTON: If the United States does not lead, there is not another leader. There is a vacuum.

SANDERS: The United States is not the policeman of the world. The United States must not be involved in perpetual warfare in the Middle East.

KARL: And on the economy and Wall Street.

MUIR: Should corporate America love Hillary Clinton?

CLINTON: Everybody should.

MUIR: And will corporate America love a President Sanders?

SANDERS: No, I think they won't. The CEOs of large multinationals may like Hillary. They aren't going to like me and Wall Street is going to like me even less.

KARL: Martin O'Malley called out both Sanders and Clinton on gun control.

GOV. MARTIN O'MALLEY (D-MD), PRESIDENTIAL CANDIDATE: Senator Sanders voted against even research dollars to look into this public health issue.