Republican presidential hopefuls gathered in New Hampshire this weekend for a two-day conference showcasing an array of possible contenders in the 2016 race. Nineteen Republican politicians, including declared candidates and others mulling campaigns of their own, aired out their political stances and tried to differentiate themselves from other contenders before a host of GOP supporters as the Republican field remains wide open.

The program included the three Republicans who have already thrown their hats into the ring – Sens. Rand Paul of Kentucky, Marco Rubio of Florida and Ted Cruz of Texas – as well as others widely expected to announce their candidacies in the months ahead -- former Florida Gov. Jeb Bush, New Jersey Gov. Chris Christie and Wisconsin Gov. Scott Walker.

A smattering of high-profile Republican politicians, including former Arkansas Gov. Mike Huckabee, former Louisiana Gov. Bobby Jindal and former Texas Gov. Rick Perry, were also on the bill.

So far, the Republican political field is still considered to be anybody’s race. A USA Today/Suffolk University poll released this week found that there were no strong front-runners on the GOP race. None of the front-runners received anything above 9 percent of support from those polled. 

The Republican Leadership Summit is considered a critical way for candidates to kick off the campaign season, establish their competing visions and find opportunities to speak at forthcoming fundraisers and high-profile events.

Marco Rubio, who announced is candidacy Monday, referred to the 2016 race as a “referendum on our national identity” and said the U.S. needed to overhaul both the Social Security and Medicare systems. Rubio’s campaign theme of a “New American Century” is considered to be an attempt to differentiate himself from both Hillary Clinton and Jeb Bush. So far, however, he’s avoided criticizing Bush, who helped guide him in the early days of his political career, but analysts predict a rift may soon emerge as the two Republicans vie for the presidency.  

Rand Paul played up some of his stances that diverged from his Republican rivals. He criticized the U.S.’ use of domestic surveillance, saying the National Security Agency’s operations were violating civilians’ rights to privacy. “It is none of the government’s damn business what you are doing on your phone,” he said, according to the New York Times. Paul has already pledged his commitment to end the surveillance programs immediately if elected president.

Paul also lambasted U.S. intervention in foreign wars, asking, “Why the hell did we ever go into Libya in the first place?”

“It is something, if you watch closely, that will separate me from [the other] Republicans,” he said, according to MSNBC. “The other Republicans will criticize Obama or Hillary Clinton on foreign policy but they would have done the same thing ten times over.”

Jeb Bush, meanwhile, expressed concern over climate change, breaking with many of his Republican peers. “The climate is changing and I’m concerned about that,” he said during an event Friday night, according to The Hill. He said U.S. industries could cut down on carbon emissions by embracing natural gas.

“We need to work with the rest of the world to negotiate a way to reduce carbon emissions,” he added.

Bush also used a softer tone than many other Republicans have on immigration, reaffirming his stance that undocumented immigrants should have a pathway to legal status and that those aiming to reach the United States are “driving for success.”

Chris Christie played up a recent set of vetoes he issued on tax increase proposals, saying he balanced New Jersey’s budget after coming into office facing an $11 billion deficit.  He discussed bringing the Social Security program into fiscal order by raising the age of eligibility or requiring larger premium payments from those with higher incomes at retirement.

Former Arkansas Governor Mike Huckabee emphasized his commitment to gun rights, which he said was the “ultimate line of defense that free citizens have to protect themselves against tyranny.” He said Friday that he would announce his decision about a possible presidential run at an event May 5.  

Meanwhile, business titan Donald Trump, who announced earlier this year he was forming an exploratory committee for a 2016 run, said he was disappointed in the entire field of Republican candidates so far.

“Politicians are never going to solve all the problems we have,” he said, according to The Hill.

“All the people you’re listening to, you can forget,” he added. “If I decide to run and win, I will make this country great again.”