A Fox News poll conducted Jan. 16-17 shows McCain with a 7 percentage point lead over Huckabee heading into tomorrow’s South Carolina Republican primary. Of the 500 registered voters likely to take part in the Republican primary, 71 percent of the respondents overall are certain to vote for the candidate they support. Romney supporters are the least likely to change their votes before tomorrow, with 80 percent responding that they are certain to cast a vote for him. But 73 percent of McCain and Thompson supporters feel the same degree of certainty. Huckabee rounds out the group of major candidates with only a 68 percent certainty score.

In a candidate-association question, McCain wins the “strong leader” comparison with 36 percent, 16 percentage points higher than Romney. He and Huckabee have almost identical scores (25 percent to 26 percent) as “honest and trustworthy,” leading the other candidates by more than double figures. But, McCain scores lower than all of the candidates other than Giuliani in the “true conservative” category, losing out there to Thompson (28 percent).

In contrast to the Gallup poll reported today about Bush’s approval ratings, the respondents polled by Fox News in South Carolina give the president a 74 percent approval rating — that score breaks down to 34 percent who strongly approve and 40 percent who somewhat approve.

The margin of error is ‘4 percent.