Yea I remember when Carson was polling 10 points ahead of Trump according to the register.
Iowa is a caucus. I expect Trump will hold his own. Of course he’ll have to deal with the razzing he’ll get if he comes in 2nd or all hell breaks lose if he slips to 3rd.
Caucus are a turn out game. It’s a good test for Trump’s viability.
Roughly only 5% of Iowans bother to show up for Caucus. It has not been a good indicator of who will win nomination.
For example HUckabee won in 2008 and Santorum won in 2012, the 2 election cycles with no incumbents running.