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
Scott Walker has also used social media, external to hit Hillary Clinton directly with both her association to Mr Obama and her time as Secretary of State - arguably her most popular role to date.
James Oliphant
Reuters reporter
Reince Prebus putting fear in crowd: Clinton will be sitting on a primary war chest while GOP nominee "probably will be broke." #SRLC2015, external
Molly Beck
Wall Street Journal Reporter
Image source, TwitterLong long line of VIP #SRLC2015, external attendees waiting to get a photo with @ScottWalker, external.
Jenna Johnson
Washington Post reporter
Scott Walker says he is the only potential candidate who can "fight and win" -- and "that's what we need to move America forward." #SRLC2015, external
Anthony Zurcher
North America reporter
Scott Walker, who has stumbled on foreign policy questions in the past, talks about a recent trip to Israel. He says he spoke to Israeli soldiers who "feel every day in Israel like we felt after 9/11".
His next line gets a standing ovation: "We need a commander in chief who will tell it like it is. Radical Islamic terrorism is a threat to this country, and we're going to do something to stop it."
Image source, APOnce again, the biggest applause line at any political gathering of Republicans involves talk about supporting Israel and confronting the Islamic State.
Alice Ollstein
ThinkProgress reporter
@ScottWalker, external on Iran: "Why are we even talking about doing a deal with 'em?" Cites the 1979 hostage crisis to back up his point.
Anthony Zurcher
North America reporter
Washington area is "68 square miles surrounded by reality," says Scott Walker.
No Republican ever lost support by bashing the nation's capital. It's also a way for a Midwestern governor like Walker to differentiate himself from the US senators running against him. The senators have to spend the bulk of their time in DC, and Jeb Bush's name has put him firmly in the "Washington insider" camp.
Anthony Zurcher
North America reporter
Wisconsin Governor Scott Walker is here, and he's busy touting his victories over liberal interests - including public unions - in his state. His ability to get conservative priorities passed in a swing state is the heart of his campaign pitch.
"You know where the Occupy Wall Street movement started?" he asks. "Madison, Wisconsin. They came and occupied our capital."
But we won that fight, he says.
Scott Walker
Wisconsin governor
Watch Gov. Walker's speech at the Southern Republican Leadership Conference LIVE http://hubs.ly/y0Q9qM0, external
Anthony Zurcher
North America reporter
Image source, APMary Fallin is introducing Scott Walker, but he apparently isn't here yet. Now we get to see the Oklahoma governor's skill at chewing up time. Always risky to have politicians talk before audiences off-the-cuff.
Anthony Zurcher
North America reporter
"Our candidates are not afraid to talk to the press," says Oklahoma Governor Mary Fallin. That's been a common line of attack against former Secretary of State Hillary Clinton, who has only answered a handful of media questions since she announced her candidacy last month.
Why isn't she more open to the press? Because she doesn't have to be. The only group less popular than politicians among the general public are reporters.
Anthony Zurcher
North America reporter
Perhaps the best suggestion for a crowded debate floor, though, is the head-to-head tournament style system devised by Ricochet's Jon Gabriel. Jeb Bush vs. Bobby Jindal, Marco Rubio vs Donald Trump. Start filling out your brackets now, external!
Jennifer Harper
Washington Times
tweets, external: 11 GOP hopefuls to Oklahoma to talk of energy, leadership and 2016 http://www.washingtontimes.com/news/inside-the-beltway/
Anthony Zurcher
North America reporter
Image source, APWisconsin Governor Scott Walker is the first presidential candidate to take the stage.
Conservative radio host Rush Limbaugh once said he has "the blueprint for the Republican Party if they are serious about beating the left". Here's a closer look at the one of the surprise front-runners of the campaign so far.
Do you have a question for Anthony about the upcoming presidential election or the candidates? Tweet to @BBCNewsUS, external and see if Anthony answers on this page.
Image source, APOne of the highest profile unofficial candidate is Jeb Bush, the former Florida governor and son and brother of presidents.
Bush hasn't declared yet. Instead, he's working closely with a political action committee, Right to Rise, which is expected to raise gobs of cash.
But with recent stumbles by Mr Bush and family presidential ghosts haunting his campaign, what would happen to all that money if he loses?
Anthony Zurcher
North America reporter
The event has taken on additional urgency with the recent announcement that Fox News will invite only the top 10 polling candidates to appear on the stage at the first presidential primary debate on 6 August.
Front-runners in Oklahoma will try to build on their leads, while those back in the pack aim to make a splash.
Thursday features candidates from both categories - Wisconsin Governor Scott Walker, followed by the two Ricks - former Pennsylvania Senator Rick Santorum and ex-Texas Governor Rick Perry.
Anthony Zurcher
North America reporter
Oklahoma City may seem like a strange place to hold a "Southern" Republican Leadership conference.
The state was called the "Indian Territory" during the Civil War, after all. And the town itself feels much more Mid-west than past heart-of-Dixie locations New Orleans, Memphis and Charleston.
But, as they say, follow the money. The guest of honour at an upcoming lunchtime "birthday bash" on Friday - Oklahoma oil industry billionaire T Boone Pickens - is a dead giveaway for why activists and candidates are descending on the state capital.
Oklahoma City is an energy boomtown. One in six jobs in the state is connected to oil and natural gas industry.
A 50-story high rise, the Devon Energy Center, towers over a downtown that is dotted by construction sites.
There's big money in Oklahoma City right now. And where money leads, politicians inevitably follow.
Anthony Zurcher
North America reporter
Image source, ReutersFor the next three days Oklahoma City will be at the centre of the contest for the Republican presidential nomination.
It's the site of the Southern Republican Leadership Conference, an annual gathering of activists and officeholders from around the South, that hotbed of conservative passion.
I'm here to report on the speeches of current and likely candidates - and speak to attendees about who is capturing their attention - and possibly their primary vote.