New Jersey Gov. Chris Christie speaks at a Republican Jewish Coalition meeting on March 29, 2014, in Las Vegas.(Associated Press Photo/Julie Jacobson)

When 14 presidential candidates all show up at the same event, you know it matters. So why are 14 GOP presidential contenders showing up at the Republican Jewish Coalition forum in Washington on Thursday?

The conventional answer is that the place will be packed with big-money donors including RJC heavy hitter Sheldon Adelson. But in truth many in attendance will have already picked their candidate. As Politico reported, Sen. Marco Rubio and former Florida governor Jeb Bush each have a flock of backers:

Bush, based on the list of hosts for the 7:30 a.m. meeting Thursday, already has solid support from a number of RJC board members. Hosts listed are Yitz Applebaum, Josh Bolten, Steve Friedman, Sam Fox, Cheryl Halpern, Fred Karlinsky, George Klein, Ronnie Krongold, Bernie Marcus, Ken Mehlman, Robert Schostak, Mel Sembler, Florence Shapiro and Zeidman. . . .

Rubio has a long list of RJC members supporting him, too: Wayne Berman, Mark Bowman, Phil Rosen, Larry Mizel, Jeffery Feingold, Elliott Lawler, Rick Horvitz, Brad Rose and Steve Louro, along with Singer, who is working his own network to secure new contributions on Rubio’s behalf.

New Jersey Gov. Chris Christie has been coming to speak to the group since his first run for governor and has deep, long-standing ties to the large Jewish community in his state. He now has an opportunity to get a rare second look from a group that would appreciate his focus on national security.

The money therefore is only a part of the picture here. In effect this is a foreign policy audition, especially on Israel, Iran and the larger Middle East. It is a way of establishing credibility with some of the most informed voters. (Candidates have 30 minutes to use for a speech or Q&A, so one point of interest will be who is comfortable enough to answer probing questions from RJC Executive Director Matt Brooks.) This is not a matter of checking the boxes (aid for Israel, not pressuring the Jewish state to give up territory, opposition to the Iran deal), but of demonstrating that candidates understand the threat aimed at both Israel and the United States posed by Islamic terrorism. Do they have a real plan to defeat the Islamic State? Do they understand the dangers that flow from Russian intervention in the region? Where do they stand on defense spending and intelligence issues?

The most critical audience interested in their answers is not Jewish Republicans (who are small in number) but Christian Zionists for whom Israel and the danger from Islamic terrorists rank at or near the top of their priority list. Three prominent Christian leaders just over a year ago set out some of the criteria they would use to assess the presidential candidates:

Does the candidate have demonstrated wisdom and proven experience on defense and foreign policy issues? What does he or she believe constitutes America’s most vital national interests, those essential to protect and defend? Does he or she truly believe in a policy of “Peace Through Strength” and have a credible plan to rebuild the military, and a plan to protect our borders and national sovereignty? Does he or she have a solid team of qualified, seasoned advisors, especially on matters related to the defense, the Middle East, Russia, Asia, and energy? . . .

Does the candidate have a clear and coherent view of U.S. vital interests in the Middle East, including a demonstrated, consistent, long-standing support for Israel and a solid understanding of why Israel matters to the U.S.? Does the candidate have a clear understanding of the urgency of the threats posed by Iran, ISIS, and Radical Islam more broadly, and a serious approach towards dealing with such threats? Does he or she have proven wisdom and experience in dealing with the Middle East issues, or is the candidate too new to the foreign policy arena?

In other words, a much larger bloc of voters — who happen to be especially influential in the Iowa caucuses and the South Carolina primary — will be listening and watching intently what the candidates say at the RJC forum, sharing their observations and making decisions about whom they will vote for and volunteer to help. Considering that a single organization, Christians United for Israel, boasts a membership in excess of 2 million voters, the stakes are high.

With national security rising on the list of voters’ concerns in many polls, the entire GOP electorate will be interested in the issues the candidates will tackle Thursday. They will be sizing up the candidates’ comfort level in addressing them and the depth of their knowledge. If the primary contest is now a tryout for commander in chief, the RJC event is a key audition.