The top 10 Republican presidential candidates, as determined by Fox News, take the stage together for the first time tonight in Cleveland at 9 ET. The other seven, who ranked lower in Fox News' analysis of recent polls, will debate earlier, at 5 p.m. ET. You can see who will be in which debate here.
Fox News has said it will try to give each candidate about the same amount of airtime, no small feat with 10 or even seven on stage. The moderators said the questions will be grouped into about a half dozen major topic "buckets," touching on foreign and domestic issues. Each candidate will get one minute to answer the question, and if he or she calls out another candidate in that time, that candidate will get 30 seconds to respond. The moderators said they hope the format "enables interaction" on the stage. The candidates and public also submitted questions on Facebook, which Fox may air during the debates.
The prime-time debate will, at least physically, take place around Donald Trump, who will occupy the center spot (determined by his lead in recent polls). And Trump's rivals may well have to revolve their answers around his outsized personality as well. That's something even the debate's moderators seemed to acknowledge.
"Part of it is also the Donald Trump show because he's been the big X factor in this entire campaign. Obviously, I think shocked the political world with how well he's done," Fox's Chris Wallace said.
NPR's politics team will host a live chat for both debates tonight, right here on this page (starting at 4:45 p.m. ET). We'll have the news, analysis, fact checking, polls and we welcome your comments, too. We're also updating the news all night at npr.org and on Twitter @nprpolitics.