Last Updated Jan 15, 2016 9:54 AM EST
On Thursday night, the Republican field gathered for the first GOP debate of 2016 in North Charleston, South Carolina, in a debate hosted by Fox Business Network.
- Republican debate analysis: Donald Trump remains as angry, unapologetic as ever
- Transcript: Sixth Republican top-tier debate
The candidates on the main debate stage at 9 p.m. ET. Thursday included businessman Donald Trump, Texas Sen. Ted Cruz, Florida Sen. Marco Rubio, neurosurgeon Ben Carson, New Jersey Gov. Chris Christie, former Florida Gov. Jeb Bush and Ohio Gov. John Kasich.
- Watch CBSN coverage of the sixth Republican debate, beginning at 7 p.m. ET
Former Arkansas Gov. Mike Huckabee and former Hewlett Packard CEO Carly Fiorina were pushed to the undercard debate, where they were joined by former Pennsylvanian Sen. Rick Santorum.
Kentucky Sen. Rand Paul qualified for the earlier debate stage but chose to sit out Thursday night, his campaign saying that he would "not let the media decide the tiers of this race and will instead take his message directly to the voters of New Hampshire and Iowa."
He made another appeal to the network for inclusion, but was rejected Wednesday. Blaming both the Republican National Committee (RNC) and Fox Business, Paul said in an interview with CNN on Thursday that it was a "big mistake" to exclude him and that he was an "important voice here."
The Fox Business criteria, released in late December, said that a candidate had to place among the top six candidates nationally in an average of the five most recent national polls recognized by Fox News, or in the top five in either Iowa or New Hampshire, based on recognized polls in those states. The business network used 17 polls during the selection process, which were listed in a memo from the network. Six different national polls were considered because two were conducted concurrently.
Cruz's eligibility to run came up during the debate -- Trump and other candidates have been raising the question of the Canadian-born candidate. Cruz was also be asked about his failure to disclose a loan from Goldman Sachs toward his 2012 senate campaign.
→ What: Sixth Republican presidential debate
→ Where: North Charleston, South Carolina
→ Time: 6 p.m. ET Saturday for the undercard debate, 9 p.m. ET Saturday for top-tier debate
→ On computer:The debate was available live and has now been posted to FoxBusiness.com
Moderators: Neil Cavuto, a Fox Business Network anchor and managing editor of business news, and anchor Maria Bartiromo will moderate the top tier debate. Anchors Trish Regan and Sandra Smith will moderate the undercard debate.
Fox Business Network has also coordinated with cable and satellite providers to unbundle the channel for viewers nationwide during the debate.