Debate participation has always been tricky for parties, eager to put their best face forward on one of those rare occasions that people are actually paying attention. As Gold reports, debate hosts have usually tried to be scientific.
In past years, Fox News determined debate qualification in part by looking at the top 10 candidates who had hit at least 1 percent in the five most recent national polls. As of now, 15 of the top 16 potential candidates have at least 1 percent, according to an average of the five most recent phone surveys testing support for the GOP nomination.
That average was calculated by the Post's poll team. The chart below shows the 16 candidates mentioned above, and their average ranking in polls since the end of March. If you're only including the top 10, it's the group in the shaded area.
So Rick Perry, who won no states in 2012, makes the cut. Rick Santorum, who won Iowa, doesn't. The aforementioned Trump gets to appear on stage; Ohio Gov. John Kasich does not.
There are various ways around this -- a higher bar, for example. We also included lines showing the range of survey results for each candidate in order to make another point: There is a lot of volatility in the polling. By the time the later debates roll around, that probably will be less of a problem. Much of the recent surging we've seen from various candidates is linked to the announcements of their candidacies, which will be old(er) news by late July. But there's a very real possibility that 10 of the many eventual candidates will be floating within two or three percentage points of each other, just as there are currently six within two points in the lower tier of the current averages. The more candidates, the less likely that a large group will definitively separate from the pack. What to do then?
Meanwhile, the Democrats seem to have finally scraped together enough candidates to actually have debates. Everyone has problems.