What the 9 Candidates Have to Lose at Tonight's Debate

As we close in on the crucial Iowa and New Hampshire elections, tonight's fifth Republican debate has the potential to shape the next crucial stretch of the race.

So far, Donald Trump is pulling away in national polls. Ted Cruz is solidifying a strong base of support in Iowa. And time is running out for other candidates to make their moves before the early primaries and caucus results come in.

Here's what each candidate has on the line during tonight's showdown:

Donald TrumpWhat he has to gain: Donald Trump has been climbing in national polls after his proposed ban on non-American Muslims entering the United States. If Trump can withstand attacks from other candidates and solidify his even wider lead, he could be a major winner of tonight's debate.

What he has to lose: Ted Cruz is closing in on the real estate mogul, according to the latest Iowa poll and many pundits think Cruz is ultimately Trump's most dangerous challenger in the fight for the nomination. A misfire against Cruz or a major blunder could give Cruz even more momentum not only in Iowa, but also nationally.

Ben CarsonWhat he has to gain: Ben Carson's recent trip to visit Syrian refugees and his planned trip to Africa in an effort to bolster his foreign policy credibility, are both points that can stop Carson's downward slide and prove that he has foreign affairs chops in a world after Paris and the San Bernardino attacks.

What he has to lose: The neurosurgeon's favorability numbers have been falling after questions about his childhood and his foreign policy experience. Another slip up tonight could cement voters' perception that Carson is inexperienced on terrorism.

Ted CruzWhat he has to gain: Ted Cruz has been in the headlines for his gains in the Iowa polls, but tonight marks Cruz's first chance to give his message to a national audience as a major player. A strong performance could vault him into national front-runner contention as well.

What he has to lose: The Texas Senator is the up-and-coming force in Iowa, but attacks from Marco Rubio, Rand Paul or other candidates jockeying to become the main anti-Trump candidate in the race could trip him up and scatter some of his support.

Marco RubioWhat he has to gain: Some think Marco Rubio may ultimately be one of the strongest GOP contenders, but his polling has remained flat since the last debate. While Rubio has had strong debates in the past, a standout moment could steal some thunder away from Ted Cruz's rising numbers and turn attention back to Rubio.

What he has to lose: Rubio's competitor, Ted Cruz surging in the Iowa polls and the first caucuses are less than 50 days away, forces him to start thinking about his moves. Major losses in the first two contests could give him an uphill climb for a possible successful run at the nomination.

Jeb BushWhat he has to gain: Jeb Bush's support has been in the low single digits now nationally, and the clock is ticking. A standout attack against Donald Trump or Ted Cruz could give him a boost in an early state or nationally - but he needs to start making his move now.

What he has to lose: Jeb Bush's campaign is struggling, but ultimately not on life support. A major gaffe tonight could scare off his last remaining donors and supporters, leaving him with an even steeper path to climb to the nomination.

Chris ChristieWhat he has to gain: A strong moment from the New Jersey Governor tonight could rocket him into contention against Donald Trump in New Hampshire, where Christie has already been raking in major endorsements over the past several weeks.

What he has to lose: He needs to make his move in New Hampshire soon. If Christie is out shined by other candidates - especially Donald Trump - it could slow any momentum he had in the state and keep him in the lower tiers of candidates.

Carly FiorinaWhat she has to gain: Carly Fiorina's strong debate skills prompted her rise to prominence in the GOP race earlier this year, and they can prompt her rise again. She needs a standout moment to show she hasn't dropped off the map.

What she has to lose: Despite her strong standing earlier this year in national and New Hampshire polling, she's dropped into the single digits, barely making the main-stage debate. If she doesn't reverse her downward spiral, this could be the last time she's on the main-stage for a debate.

John KasichWhat he has to gain: John Kasich has been kept on the fringes of the debate stage so far this cycle and needs a breakthrough moment to start garnering support in New Hampshire. He hasn't been afraid to go after Donald Trump before: a well-executed attack could make him stand out from the crowd.

What he has to lose: Kasich has limited national support, but has some backing in New Hampshire. With Christie soaking up several major New Hampshire endorsements, Kasich stands to lose his last remaining foot in the door for a viable run at the nomination.

Rand PaulWhat he has to gain: Rand Paul will be on the attack, trying to differentiate himself from Ted Cruz, Donald Trump and Marco Rubio as a viable alternative for the nomination. So far though, Ted Cruz has been soaking up his main bloc of voters.

What he has to lose: The Kentucky Senator barely made it onto the debate stage this time. A failure to stand out and start gaining momentum could solidify Cruz's status as a top-tier candidate and make him fall off the debate stage.