Wisconsin Gov. Scott Walker, a prospective presidential candidate, has emerged as one of the frontrunners in the race for the Republican nomination, topping several polls. (Michael Reynolds/European Pressphoto Agency)

The annual gathering known as CPAC (Conservative Political Action Conference) is a ritual of the political calendar, a multi-day speechathon, a forum for budding presidential candidates and a winter carnival all rolled into one.

Hosted by the American Conservative Union (ACU) and sponsored by a who’s who of conservative organizations, CPAC has grown steadily over the decades. It is a testing ground, if not always a proving ground, for rising politicians. This year will be no different.

Coming at the start of the 2016 presidential cycle, at a moment when the campaign seems to have hit warp speed (perhaps only temporarily), what happens at CPAC will reverberate widely and instantly through conservative and other circles. What proves lasting is another matter.

“Conservatives are hungry to find a standard-bearer, but they’re open to who it is,” said Matt Schlapp, the new chairman of the ACU. “They’re actually shopping right now. . . . How [the candidates] execute will have a huge impact on where the race goes next.”

The contest for the Republican nomination has been changing constantly almost from the day the 2012 election ended. Various Republicans have enjoyed a moment in the early spotlight. Strategists for prospective candidates — at least some of those buried in the early polls — hope and believe that pattern will continue.

Sen. Marco Rubio (Fla.) was seen as the party’s savior two years ago, when his leadership on immigration reform drew national attention. New Jersey Gov. Chris Christie was seen by some as the one to beat in the aftermath of his reelection victory in November 2013. The ebb and flow has produced moments for others. Sens. Ted Cruz (Tex.) and Rand Paul (Ky. ) both have excited audiences of activists and risen in prominence.

But right now the focus is elsewhere. Former Florida governor Jeb Bush, who stepped out earlier than expected, has been a winter favorite, especially of the GOP establishment and donor network. Wisconsin Gov. Scott Walker has ridden a booster rocket over the past month to the top of many polls and become an instant star nationally.

The party is fractured, as the debate on Capitol Hill this week over funding the Department of Homeland Security underscores. On the presidential front, many conservatives are still frustrated by the results of the past two GOP nomination campaigns. Those contests gave the party Arizona’s Sen. John McCain in 2008 and former Massachusetts governor Mitt Romney in 2012 — neither of whom was seen as truly or authentically conservative to many in the GOP base.

“Conservatives haven’t loved John McCain or Mitt Romney,” Schlapp said. “But eight years of President Obama is a real unifier, and they want to win [in 2016]. They want to pick some justices for the Supreme Court. They want to control the regulatory process. The spirit of 2015 is let’s find a horse who can win.”

CPAC will conduct a straw poll, as it has done for many years, with results to be announced on Saturday as the event is ending. The balloting has been a poor indicator of general Republican Party sentiment.

Reflecting the strong libertarian bent of many of the conference attendees, someone with the last name of Paul has led the field in four of the past five years. Rand Paul won in both 2013 and 2014. His father, former Texas congressman Ron Paul, won in both 2010 and 2011. Romney won in 2012 in the heat of the nomination contest.

The past three years have produced three different second-place finishers: Cruz in 2014, Rubio in 2013 and former House speaker Newt Gingrich in 2012. Romney was the runner-up in 2010 and 2011.

Schlapp said he expects coverage of the straw poll to highlight “who popped” or did better than expected. Candidates who don’t do well will dismiss the poll as not reflective of the electorate that will choose the nominee in 2016.

Schlapp and the others helping to organize this year’s conference have made changes in the format. This year, speakers will take questions rather than just deliver speeches. Each of the prospective 2016 candidates will be allotted 20 minutes. They will speak for roughly 12 minutes and take questions for the rest. Bush, whose stump speaking style has been criticized as flat, has opted to do his entire appearance in a question-and-answer format, where he has done better in recent appearances. Fox News host Sean Hannity will do the questioning.

Schlapp said the organizers are aware that attending the conference is not a cheap ticket for most of the people who fill the hotel ballroom. Most pay their own air fare and hotel bill. “We want to make sure they get the absolute best interaction with the speakers,” he said.

Performance is the key to CPAC: who lights up the room and who doesn’t. “It’s going to be about the execution and how do they think on their feet when they get questions,” Schlapp said.

Expectations will vary depending on each candidate’s place along the spectrum. “Those candidates who are considered crowd favorites of conservative activists are going to have to perform well,” he said. “Those candidates who are not considered that type of candidate, the bar is probably lower.”

He did not elaborate on that, but his answer suggests that the bar is lower for Bush or Christie than for, say, Cruz or Paul. Others see the event as vitally important for Bush as he seeks to overcome skepticism among conservatives that he is too moderate.

This year, the speakers have been encouraged to do more than simply deliver a series of applause lines. What organizers hope is that the speakers will not just arrive with canned attacks on the president or Obamacare designed to rouse the audience but instead will offer something thematic and topical in their prepared remarks.

Schlapp also believes the question sessions could be the most interesting. “The Q-and-A gives them a chance to be spontaneous and to make news — not in a negative way but in a positive way,” he said. “I think it makes them nervous that the format has changed. It could be high-risk, but it could also be very high-reward.”