The last GOP debate of 2015, and the fifth if you're keeping score, is going down tonight at the Venetian Casino in Las Vegas. The Republican candidates, which tonight includes Gov. Chris Christie (who missed the last main stage debate) after a surge in poll numbers, will have tons to argue about,focusing on terrorism and combating ISIS after being jolted by the attacks in Paris and the San Bernardino shooting. Donald Trump, who goes into the debate leading his opponents, is expected to target Sen. Ted Cruz who's just gotten a boost in the polls becoming someone to look out for in the presidential race. Here's what the GOP presidential candidates had to say about national security, terrorism, and more.   

Rand Paul uses his opening remarks to tackle Trump's terrorism plan while also taking a swing at the confusing concept that is the world wide web. "Trump says we should close that Internet thing,” said Paul. “If we do that, I think the terrorists have won."

Ben Carson chose to observe a moment of silence—literally, a moment—for the victims of San Bernardino. 

Trump responds to his controversial plan to keep Muslims out of the U.S. saying, "We're talking about security. People are pouring over our southern border." He reminded people of his plans to build a wall: "I will build a wall. It will be a great wall." 

Jeb Bush rebutted Trump's plan and dropped the ultimate Jeb jab: "Donald is great at the one-liners. But he's a chaos candidate, and he'd be a chaos president." Trump retaliated and said Bush's campaign has been a "total disaster" earning boos from the crowd. 

Paul slams Rubio, calls him the "weakest" candidate on immigration saying,"Marco has more of an allegiance to Chuck Schumer and the liberals than he does to conservative policy."

Carson declares war on political correctness and calls it “nonsense” saying “we need to be suspicious of possible radicalizing everywhere. 

When asked about his brother, former president Bush saying "Islam is peace" while visiting a mosque just days after 9/11, and if he shared that opinion Jeb said  "If we want to destroy radical Islamic terrorism, we can't disassociate ourselves from peace-loving Muslims.” 

On responding to terrorism:

Cruz said his strategy would take from the first Persian Gulf War and how the U.S. allegedly launched 1100 carpet bombs for 37 days straight and then "mopped up what was left of the Iraqi army." He noted, "Political correctness is killing people." 

Rubio said he would carpet bomb ISIS, but opposed Cruz's plans for airstrikes. Rubio thinks an on-the-ground effort is necessary to take down ISIS. He called out Cruz for cutting down funding for military operations that would help solve this problem.

In another attack on Trump's capability to be a president Bush landed this verbal beatdown: "You're not gonna be able to insult your way to the presidency. Leadership is not about attacking people or disparaging people…"

Paul jumps on the Trump beatdown and asks "Is Donald Trump a serious candidate?" He questions his plan to shut down parts of the internet and essentially violate first amendment rights.

The Bush and Trump back and forth (with Bush unanimously winning) has spawned this very accurate GIF of the situation:

The Trump backlash has taken over Twitter. The hashtag #WhitesAgainstTrump is now trending with accounts from people who are white saying they're against Trump.

Cruz says "mythical, moderate rebels" in Syria are "like a purple unicorn" because they don't exist. Cruz doesn't elaborate his thoughts on white unicorns. 

Fiorina criticizes Trump for sounding like Barack Obama, "That is exactly what President Obama has said, I am amazed to hear that."

On Russia:

Kasich: "We need to punch the russians in the nose" because they "threatened our allies" in Europe. 

Christie: He dumps on Obama for being a "feckless weakling" when handling Russia. He absolutely says he'd shoot down a Russian plane if it were to violate a no-fly zone.  Paul critiques Christie: "if you're in favor of WWIII you have your candidate" and roasts him for bridge gate saying he shut down a bridge on a whim. 

Trump goes on a rant about CNN asking Bush questions that always begin with things he said. He said it wasn't fair and said he was being used for ratings. Bush seizes the moment and says "imagine what it's like dealing with Putin" and ISIS. Bush tells Trump he can't keep "sulking your way to the presidency." An angry Trump yells back at him and says "I'm at 42 and you're at 3" talking about his poll percentage versus Bush's.

Cruz talks about securing the border because it goes hand in hand with national security and says he'll seek help from Trump: "We'll build a wall that works, and I'll get Donald Trump to pay for it."

Christie addresses the question of whether it is the Christian way to turn away refugees and says national security is far more important.  "I'm not going to let Syrian refugees—any Syrian refugees—in this country," he said.

On par with the candidates calling out Obama throughout the night Cruz bluntly says, Cruz: "All 9 people on this stage would be infinitely better" than Obama.