South Carolina Democrats vote in just over a month on which candidate they want as the party's presidential nominee, and the people who want that job are gathering for a debate.

Sunday's contest will be the last chance for the presidential hopefuls to face one another before the first two nominating events of the election season-Iowa on February 1 and New Hampshire on February 9.

In tweets from their campaign staffs, Clinton and Sanders both called for O'Malley to be included in the debate hours after the criteria was announced.

At a rally in December, Ted Cruz said, "They keep scheduling the Democratic debates at like 2 a.m. on Alaska PBS".

Martin O'Malley has squeaked into this Sunday night's NBC News/YouTube Democratic presidential debate after poor poll numbers put his status in doubt.

The debate is hosted by the Congressional Black Caucus and the South Carolina Democratic Party.

"Governor O'Malley is looking forward to it", said campaign spokesman Sean Savett.

A Marist/Wall Street Journal/NBC News poll released earlier this week showed Sanders leads Clinton by 14 percentage points in New Hampshire. NBC Nightly News anchor Lester Holt will be the main moderator, joined by the network's Andrea Mitchell. You will be able to watch the debate directly on NBC stations besides and, Apple TV through tvOS Appstore, Roku, NBC News Android app, Amazon App, FireTV, NBC News app.

The debate, scheduled for 8 p.m. Sunday, is in the same slot as PBS' popular period drama "Downton Abbey" and airs right after two National Football League playoff games.

Republican candidates debate on Thursday night at the North Charleston Performing Arts Center.