Okay, so it’s not really a “debate” per se. And it’s certainly not sanctioned by the Republican National Committee. But a panel discussion set for this weekend that will be attended by some of the 2016 election cycle’s most talked-about prospective candidates and moderated by ABC News White House Correspondent Jonathan Karl will undoubtedly be packed with presidential politics.

At the group’s winter meeting Sunday in Palm Springs, California, Texas Sen. Ted Cruz, Kentucky Sen. Rand Paul, and Florida Sen. Marco Rubio will participate in a panel discussion on domestic economic issues, including health care and energy policy. ABC News chief White House correspondent Jonathan Karl will moderate the discussion.

The Arlington, Virginia-based Freedom Partners is a not-for-profit advocacy group affiliated with Charles and David Koch, two of the country’s best known conservative mega-donors.

The hour-long “American Recovery Policy Forum” featuring the senators is a first of its kind for the organization. It’s an attempt to have the organization play a more active role in shaping the national political dialogue, according to James Davis, a spokesman for Freedom Partners.

Though none of these prospective candidates have gone so far as to announce a presidential bid or even the formation of an exploratory committee, all of them are preparing for a run or making the case for their candidacy. It’s wise to expect some fireworks. If these Republicans are going to run a successful race for the GOP nomination on 2016, they will all have to overcome a substantial hurdle: Explaining to the Republican electorate why it would be wise for Americans to again send a first-term senator to the Oval Office.

Should he run, Rubio will attempt to surmount this impediment to his electoral prospects by framing himself as the most competent manager of America’s foreign affairs. More so, in fact, than any of the Republican candidates who served as a governor ever could.

“The next president of the United States needs to be someone who has a clear view of what is happening in the world — a clear strategic vision of America’s role in it, and a clear tactical plan of how to engage America in global affairs,” Rubio told reporters on Wednesday. “And I think for governors, that’s going to be a challenge — at least initially — because they don’t deal with foreign policy on a daily basis.”

Cruz is staffing up for a likely presidential bid and, according to one “Republican insider,” is honing a message designed to appeal to those GOP primary voters “who have the highest anger score.” As Allahpundit noted yesterday, the intensity of Cruz’s loyal support among base Republican voters and his carefully cultivated anti-establishment persona might be sufficient to overcome doubts among Republicans about his level of professional experience.

Only Paul can challenge Cruz’s claim to being the most prominent thorn in the Republican establishment’s side.

The Daily Beast’s Olivia Nuzzi recently asked if one of Paul’s libertarian supporters who now serves as a social media outreach coordinator for the Kentucky senator is a ticking time bomb. She observed that the Washington Free Beacon noted that the woman, who goes by the handle Libertarian Girl, has attacked Republicans as jingoistic warmongers and advocated for awarding NSA leaker and Russian defector Edward Snowden the Nobel Prize. This doesn’t seem like a problem for Paul at this stage of the race so much as it is an asset.

Paul’s base of support is the anti-war, pro-retrenchment wing of the GOP that has nowhere else to turn but to the Kentucky senator. This is his floor of support, and it provides some critical enthusiasm that will only help his campaign stand out from the pack. If this element of Paul’s base does become a liability, it will not be until his campaign begins to build some momentum.

With so many stark contrasts among these three prospective presidential candidates, it would be hard to justify a cordial gabfest at this weekend’s panel discussion marked by nothing more than polite disagreement. And, knowing Jon Karl, he will do his best to get the conversation headed in a contentious direction. This should get quite interesting.

This will not be the only event this weekend in which some likely presidential candidates will be speaking. The Iowa Freedom Summit will feature a range of prospective candidates including Cruz, Rep. Marsha Blackburn (R-TN), Mike Huckabee, Carly Fiorina, Rick Santorum, Jeb Bush, Ben Carson, and Rick Perry. The 2016 cycle is truly underway.