It's an arbitrary number. With the Iowa caucuses coming up, and 60% of likely caucuses saying they could still change their minds, I'd say anyone could still be a surprise. Personally, I doubt it will be Paul or Hunter, but it is possible.
Of the others, they are all significant enough nationally that they are "in play". In fact, Huckabee is the least strong in this department, being a "national" presence only by a short-term "boomlet" in the polls that is already starting to fade. In the meantime, you have Thompson working a strong ground game in Iowa, and starting to show results there accordingly, both in endorsements and in some polls.
There's no point quitting at the end of the 3rd quarter when you're only down by 14 points.
‘Why 15? Why not 10? or 5? or 20?
It’s an arbitrary number.’
Uemmm, no, its not ‘arbitrary’ I use that specifically, because of what happened in Iowa in 2004.
Do you remember where John Kerry was heading into Iowa?
10 percent, your toast. 5 percent, your Ron Paul.
15 - 209 percent, your ‘viable’ for the moment.