Standing next to Trump in the debate didn't hurt him either. And there are still two more debates in January when the more apolitical people will start paying attention.
With a margin of error of 7% this poll is useless.
PPP just released a poll that has Trump ahead in Iowa:
http://www.publicpolicypolling.com/pdf/2015/PPP_Release_IA_121515.pdf
Er, no. Trump has been gaining consistently in IA, up from the 19 range when Carson was ahead to 31 in this poll. Yes, Cruz has moved faster, but it’s simply wrong to try to portray Trump as “flat.” He is exactly where he is in almost every national and other state poll.