Republican debate live updates: GOP rivals attack Nikki Haley; Christie goes after Ramaswamy

The fourth Republican presidential primary debate is underway in Alabama, where four GOP candidates — Florida Gov. Ron DeSantis, former U.S. Ambassador to the U.N. Nikki Haley, former New Jersey Gov. Chris Christie and tech entrepreneur Vivek Ramaswamy — have taken the stage in one of the last opportunities to make their case to voters before next month's Iowa caucuses.

Former President Donald Trump, the Republican frontrunner, is once again not taking part in the debate. He participated in a Fox News town hall on Tuesday.

The primetime debate, which is being held at the University of Alabama in Tuscaloosa, is airing on the cable news channel NewsNation and its network television partner, the CW, and is being livestreamed on NewsNation's website as well as on Rumble.

Moderators include Elizabeth Vargas, a former ABC News anchor who has her own show on NewsNation; Megyn Kelly, the former Fox News and NBC News anchor; and Eliana Johnson, editor in chief of the Washington Free Beacon.

Yahoo News is providing live updates and analysis the debate in the blog below.