Following last week’s Fox News debate for the Republican presidential candidates, the packed GOP field will have another opportunity to make their case to the American public thanks to former First Lady Nancy Reagan. A total of 16 candidates for the Republican presidential nomination have been invited to participate in the CNN/Reagan Library presidential debate on September 16, an event that could help decide the GOP pecking order as the election season ramps up.

Not every Republican presidential candidate will be eligible to participate in the upcoming debate. According to a recently released set of requirements, a GOP candidate who wishes to participate must achieve an average of one percent or more votes in a specific selection of national polls. The top 10 candidates (according to an average of national polls between July 16 and September 10) will duke it out during â€śSegment Bâ€ť of the debate, while the next six highest polling candidates will participate in â€śSegment A.â€ť

All of the top ten contenders in last week’s Fox News/Facebook debate have already been invited to join the September 16 debate. They include Donald Trump, Jeb Bush, Scott Walker, Mike Huckabee, Ben Carson, Ted Cruz, Marco Rubio, Rand Paul, Chris Christie, and John Kasich. All but one of the seven participants in last week’s pre-debate â€“ Rick Perry, Rick Santorum, Bobby Jindal, Carly Fiorina, Lindsey Graham and George Pataki â€“ have also been invited, with former Virginia Govenor Jim Gilmore finding himself ineligible to join just yet. He still has a chance if he can get the required one percent by the September 10 deadline.

Whereas the Fox News debate had the two groups of candidates battle it out during events that were aired hours apart, the September 16 debate will be aired back-to-back, offering several hours of political discourse — presumably all in prime-time — that could make or break certain campaigns. The CNN debate will be held Air Force One Pavilion at the Ronald Reagan Presidential Library, moderated by CNN anchor Jake Tapper.

“Debates are a crucial part of the election process, and I’m thrilled that so many qualified candidates have the opportunity to be heard at the Reagan Presidential Library,” said Nancy Reagan in a press release announcing the debate. Reagan hosted a similar debate during the 2012 presidential election, which was held on September 7, 2011, at the Reagan presidential library.

Check out some of the frontrunner Donald Trump’s highlights (or lowlights, depending on how you look at it) from the first GOP debate.