The sixth Republican presidential debate is taking place less than three weeks before the Iowa caucus with Donald Trump still holding a firm national lead. The race in Iowa remains tight, though, and there is still plenty of time for candidates to change voters' minds.
Some things to watch for during the Fox Business debate at the North Charleston Coliseum in South Carolina Thursday night:
The lineup of candidates in the main debate topped out at 11 in September and has slowly crept down ever since, as some dropped out of the race and others were banished to the undercard debates.
With Carly Fiorina and Sen. Rand Paul (R-KY) slipping below the polling threshold Fox Business set for Thursday's debate, there will be seven candidates on stage at 9 p.m. ET: Donald Trump, Sen. Ted Cruz (R-TX), Sen. Marco Rubio (R-FL), Dr. Ben Carson, Jeb Bush, Chris Christie, and John Kasich.
Republican strategist Ford O'Connell said the increased time in the spotlight Thursday could be particularly problematic for Trump.
"If you're Donald Trump, the field can't get large enough," he said. Trump's goal will likely just be not to damage his standing in the polls, so the less time he has to talk, the better.
"I'd be lying if I said all eyes won't be on Donald Trump and Ted Cruz," O'Connell said.
O'Connell cautioned against the non-confrontational approach for Cruz. "You cannot look timid and complacent, particularly on the citizenship issue."
Cruz may have hoped to solidify his support before pivoting to take on Trump, but if that has not happened yet, he cannot wait any longer.
"He's delayed it long enough," O'Connell said, "and now the inevitable is coming."