Postpublished at 22:57 British Summer Time 21 May 2015
And that concludes our live coverage from Oklahoma. Thanks for joining us.
For more coverage of US politics and the 2016 race check out Anthony's blog.
Summary
Anthony Zurcher, our North America reporter, is in Oklahoma for a Republican leadership conference
Scott Walker, Rick Perry and Rick Santorum are among the 2016 names on day one
Republicans face a crowded primary for the 2016 nomination, with as many as 20 major candidates expected
Ask Anthony your questions about the Republican presidential candidates and their policies via @BBCNewsUS
Postpublished at 22:57 British Summer Time 21 May 2015
Jeb and Tedpublished at 22:53 British Summer Time 21 May 2015
Anthony Zurcher
North America reporterThe curtain has come down on the first day of the Southern Republican Leadership Conference.
Image source, ReutersTomorrow has the meat of the political line-up, with scheduled appearances from former Florida Governor Jeb Bush, New Jersey Governor Chris Christie, Louisiana Governor Bobby Jindal, Florida Senator Marco Rubio, South Carolina Senator Lindsey Graham and Texas Senator Ted Cruz.
Mr Cruz, the keynote speaker at the evening's dinner gala, appears to be a favourite among the crowd here, who are anticipating his appearance.
All eyes will be on Mr Bush in particular, however, as he looks to recover from what was a rough week of questions about the Iraq War and how he differs from his brother, former President George W Bush.
'What we need'published at 22:27 British Summer Time 21 May 2015
Anthony Zurcher
North America reporterRick Perry got a warm reception from the crowd here in Oklahoma City. What was it that caught their eye?
"I like his confidence, I like his executive experience, I think what he said is what we need," says Donna Hughes of Ardmore, Oklahoma. "I am really thrilled that he gave a good speech."
She says she still hasn't settled on a candidate, however. "I want to hear from all of the speakers."
Overcoming the Oops!published at 22:19 British Summer Time 21 May 2015
Anthony Zurcher
North America reporterThe term "dark horse" gets thrown around lightly. Anyone who's back in the polls seems to qualify for the label, no matter how long their odds.
Texas Governor Rick Perry deserves the label, however. While his support is low right now - according to RealClearPolitics his 2.4% national support is only good for ninth place - he has the resume and the political skill to make a move.
Image caption, Left - Rick Perry on the night of "oops" in 2011, Right - Today in Oklahoma City
Given how he ended his 2012 race for president, with an embarrassing "oops" gaffe during a Republican debate and defeats in Iowa and New Hampshire, that may be a bit of a surprise. But doubters should remember that Mr Perry was the longest-serving governor in Texas history for a reason. He's a skilled politician and a talented public speaker.
Those abilities were on display on Thursday, as he blended red-meat foreign policy lines with a populist streak that could appeal to grass-roots Republicans.
"Capitalism is not corporatism," he said. "It is not a guarantee of reward without risk. We need to return hope and opportunity to our Main Street citizens."
For a brief moment in 2012, before the stumbles, Mr Perry was considered a front-runner for the Republican nomination. It'll be a long climb to return to that status this time around, but Americans love a political comeback story.
Presidents past and presentpublished at 22:09 British Summer Time 21 May 2015
"We made it through Jimmy Carter, we'll make it through the Obama years," Mr Perry says, holding out a long pause in this part of his usual speech. "Believe me."
Image source, Getty ImagesObama and Oklahomapublished at 21:54 British Summer Time 21 May 2015
Anthony Zurcher
North America reporterThe audience here likes Rick Perry - probably because, as the governor of a neighbouring state, he knows what makes this Oklahoma-centric crowd tick.
He talks immigration - "it's time for Washington to do its job and secure our borders" - and gets a standing ovation.
He bashes Obama's energy policy -"Barack Obama is pro-energy, except he opposes drilling for it, transporting of it or the exporting of it" - and gets cheers.
"I was born just a few hundreds of miles from here," he says, "in a little place called Haskell County."
Texans and Oklahomans have a bit of a rivalry - at least on the football field - but that seems water under the bridge right now.
Rick Perry returnspublished at 21:42 British Summer Time 21 May 2015
The last Republican presidential hopeful to take the stage on Thursday in Oklahoma City is former Texas Governor Rick Perry. He's set to announce his formal candidacy a few hundred miles south of here, in Dallas, on 4 June.
Just like Rick Santorum, he dives immediately into foreign policy and the Islamic State's recent gains Iraq.
"Isis is taking areas that we had secured with the treasure of American blood," he says.
Then: "This season of chaos doesn't have to last… There is nothing wrong in America that a change of leadership can't fix."
Image source, ReutersSantorum in reviewpublished at 21:33 British Summer Time 21 May 2015
Anthony Zurcher
North America reporter
Image source, APFormer Pennsylvania Senator Rick Santorum likes to remind people that he finished second to Mitt Romney in the 2012 race for the Republican nomination. He ended up winning 11 states, including first-in-the-nation Iowa.
Like Top Gun, however, there are no points for second place. And this time around, he's in a much more crowded field. According to the latest RealClearPolitics poll, his national support stands at 2.3%, good enough for 10th place.
Mr Santorum's campaign pitch - and his speech today - centred around national security and helping the "the little guy". He says the Republican Party is the party that supports the little guy, but often they don't get that point across to voters.
Needless to say, Mr Santorum thinks he's the man to change that.
Postpublished at 21:25 British Summer Time 21 May 2015
Anthony Zurcher
North America reportertweets, external: "I won the Iowa caucus in 2012, but I started out at 4%, @RickSantorum says about current low poll numbers. "
Postpublished at 21:14 British Summer Time 21 May 2015
Reid J. Epstein
Reporter, The Wall Street Journal.
Image source, Getty ImagesI suspect John Mellencamp won't be happy that Scott Walker came out to SRLC to his "Small Town."
The liberal rocker has previously said he supports union rights and says Walker should think about that before using his songs in political events.
Postpublished at 21:12 British Summer Time 21 May 2015
Justin Dougherty
Anchor-Reporter for KWTV-News 9"We're going to win this election and we are going to unite this country... Pro growth. Pro worker. Pro family." - Santorum #SRLC2015 , external
'Blue collar conservative'published at 21:05 British Summer Time 21 May 2015
Anthony Zurcher
North America reporter
Image source, ReutersImage caption, Santorum chats with some Iowa voters
Rick Santorum likes to tout how he's a "blue collar conservative".
Some are arguing we should "open the borders, and keep labour costs down," he says. "The problem is, you are labour costs," he adds, pointing toward the audience.
We need to reduce the number of illegal immigrants in the US who are competing against low-skilled native workers, he continues.
How do we do that? He says he's "open to suggestions".
Rethinking Iraq?published at 20:55 British Summer Time 21 May 2015
Image source, Getty ImagesIt's not just a popular Republican attack line - the recent fall of Ramadi, capital of Iraq's Anbar Province, to IS forces - has commentators questioning whether Mr Obama needs a new strategy - or any strategy at all - in Iraq.
Postpublished at 20:50 British Summer Time 21 May 2015
Jenna Johnson
Washington Post reporterAT #SRLC2015, external, Rick Santorum says many low-income mothers don't get married because then they might lose their welfare benefits.
Knives outpublished at 20:48 British Summer Time 21 May 2015
Anthony Zurcher
North America reporterThis is the difference between being a front-runner and toward the back of the pack - Governor Scott Walker doesn't mention his competitors for the nomination at all. Senator Rick Santorum, who is polling in the low single digits, doesn't have that luxury.
"We can't have a nominee against Hillary Clinton who sees commander in chief as entry level position," he says, taking dead aim at candidates like Mr Walker. "We need someone who has experience, who has served in Washington on foreign policy committees… We don't want a candidate who represents the party whose foreign policy experience is a briefing book."
Touting your Washington experience isn't a big applause line, but it's what's in Mr Santorum's hand - and he's playing it.
More focus on foreign policypublished at 20:43 British Summer Time 21 May 2015
Anthony Zurcher
North America reporterRick Santorum's speech is almost entirely on the Middle East and foreign policy. "ISIS was created by Barack Obama," he says, adding that reporters should ask Hillary Clinton if she supported President Obama taking troops out of Iraq.
After Ramadi fell to the Islamic State on Sunday, we're seeing more and more sharp criticism along these lines.
Postpublished at 20:34 British Summer Time 21 May 2015
Jim Antle
Washington Examiner reporterAfter saying Obama created ISIS, Santorum says beating up on the president not sufficient. #SRLC2015, external
Santorum on stagepublished at 20:33 British Summer Time 21 May 2015
Anthony Zurcher
North America reporter
Image source, ReutersImage caption, Rick Santorum in Iowa last week
Rick Santorum is on the stage now, talking about how much he loves Oklahoma.
He's set to formally announce his presidential candidacy in Pennsylvania on 27 May.
'He's done what he's said he'll do'published at 20:26 British Summer Time 21 May 2015
Anthony Zurcher
North America reporterWe've heard from Scott Walker. But why do his supporters back him over all the competition in this crowded field?
John Hubanks of Oklahoma says: "I like what he's done in the state of Wisconsin. He's done what he's said he'll do. He's not afraid to fight and take on all opposition."
Walker in reviewpublished at 20:20 British Summer Time 21 May 2015
Anthony Zurcher
North America reporter
Image source, ReutersScott Walker has wrapped up his speech. It was pretty much his standard campaign boilerplate - complete with his Kohls shopping story, external - and the audience seemed relatively unengaged. That marks a contrast with the reception he received in Iowa in January, which helped rocket him to the top of the polls.
He's still at the front of the pack, according to the latest RealClearPolitics poll aggregate, external, at 13.2%, good enough for a second-place tie with Marco Rubio, who will speak here tomorrow.