A few things to keep in mind...
Trump is ahead by a mile in early states such as NH, SC, NV, FL over all others including Carson.
This CBS/NYT national poll had 575 voters polled nationwide, including NY, CA, IL, and all other late primary states with huge liberal populations.
The nominee will be pretty much decided after super Tuesday March 1st. Trump is comfortably ahead in every state except Iowa by super Tuesday.