South Carolina primary live – Rick Perry pulls out

Rick Perry with wife Anita and his son Griffin after announcing that he is pulling out of the Republican presidential race. Photograph: ERIK S. LESSER/EPA

7.30pm: Thanks for all your comments today – join Richard Adams for our live debate blog here.

6.15pm: Ewen MacAskill thinks tonight's debate here in Charleston will be for the first time essentially "a two-man affair, a duel between Mitt Romney and Newt Ginrgrich, with the South Carolina primary at stake".

Tonight's debate is on CNN and starts at 8pm. Richard Adams will be live blogging the full excitement – join us back here for then. That's all for now.

5.08pm: Cain entered to a pretty sparse crowd, reports our man on the scene, Adam Gabbatt.

Cain told the audience at the College of Charleston: "I have been asked repeatedly for the last several weeks and couple of months: 'Who am I going to endorse?'

"I have said consistently: 'The unconventional candidate that ran an unconventional campaign and achieved surprising results." The crowd grew quiet. "The media is not going to like it," Cain continued.

Stephen Colbert? A second endorsement for Newt Gingrich? Rick Santorum? Nope.

"Here is my unconventional endorsement. Not a candidate seeking the nomination. Not someone who is not running. My unconventional endorsement is the people. We the people of this nation are still in
charge."

You can even watch the whole embarassing saga on this video shot by Janine Gibson.

4.47pm: Herman Cain has arrived in Charleston for the Stephen Colbert event tomorrow that I mentioned earlier. He did a turn at the Southern Republcan Leadership conference just now – and led the crowd to believe he was going to announce an endorsement. He said it would be "unconventonal" and that the "media would not like it", before saying he was endorsing ... "the people".

Sound of tumbleweed

4.41pm: Whatever happened to Newt's tax returns? He was supposed to be publishing them today. Ah well, he's been a bit busy, what with an ex-wife to trash, er, sorry, not comment on.

4.11pm: Mitt Romney called Rick Santorum earlier today to "congratulate" him on the flipped result in Iowa. But now, after Santorum revealed the call, the Romney camp is denying it was a "concession" call, saying he was just being a "good sport". Fox News anchor Brett Baier quotes Santorum as saying: "Well then, what was he congratulating me for?"

3.38pm: A few commenters have asked why we haven't picked up on Stephen Colbert's campaign in South Carolina. The answer is that it has been a pretty busy day. But here goes: Colbert has announced that he is to hold a rally here in Charleston on Friday with Herman Cain.

The satirist is urging his "supporters" to vote for Cain, whose name is still on the South Carolina ballot, because he had missed the deadline. The event, which starts at 1pm, is called the Rock Me Like A Herman Cain: South Cain-olina Primary Rally.

Stephen Colbert, centre, and John Stewart, on The Colbert Report. During the episode, Colbert legally transferred his super political action committee to Stewart, his friend and Comedy Central cohort. Photograph: Kristopher Long/AP

Earlier this week, the pro-Colbert super pac, Americans for a Better Tomorrow, Tomorrow, released an ad in support of Cain, in which Cain did not appear. The ad made it look like Colbert was Cain. If you get my drift.

3.22pm: There's an important update on the quotes critical of Newt Gingrich attributed to Michele Bachmann by a newspaper in Greenville, which I reported earlier today. The Bachmann campaign, according to Politico, says they are "fake". The Greenville News points out in its story that the statement claimed to be untrue was sent from the same email address as the new, official one.