A new Pew survey has come out showing that Donald Trump is still in the front of the GOP pack with Carson a semi-distant 2nd place. But 3rd, which belongs to Fiorina and Rubio, is even more distant:
It looks like this poll of Republican-leaning potential primary voters was given to around 500 people, with an error of close to +/- 5%. You can read more about the poll here.