As the Republican candidates prepare for their next debate Thursday night in North Charleston, South Carolina, Donald Trump will once again be center stage -- as a result of the Fox Business Network's calculations of who has done best in various trial heat polls nationally and in key states.

Despite his poll standing, Trump's image among Republicans is certainly not the most positive of the major candidates, and new calculations show that Trump has by far the worst image of any major Republican candidate among Democrats and independents.

These results are based on Gallup Daily tracking data collected between Dec. 1, 2015, and Jan. 11, 2016. This analysis uses the "first question" party identification groupings, based on Americans' initial answers when asked if they identify as Republicans, independents or Democrats. (For most of our Gallup analyses, we use the "leaned" party groups that include independents who, in response to a second question, say they lean toward one party or the other.)

During the Dec. 1-Jan. 11 time period, Trump's overall image was 33% favorable and 58% unfavorable, for a net favorable rating of -25. Among "pure" Republicans, Trump's net favorable rating was +27 -- sixth out of the nine GOP candidates we are tracking. But the new analysis shows how deeply negative Trump's image is among Americans who don't identify as Republicans, with a net favorable rating of -70 among Democrats and -27 among independents, by far the most negative of any candidate.

The next GOP candidates rated most negatively among Democrats are Ted Cruz and Mike Huckabee, with net favorable ratings of -37 and -34, respectively. The one candidate who does "well" among Democrats on a relative basis is John Kasich, at only a -4 net favorable rating. Among independents, the next most negative GOP candidate after Trump is Jeb Bush.

Trump is the best-known GOP candidate among Democrats, and this could be a factor in his low ratings, since there are more Democrats to give him a negative score. For example, at the extremes, 94% of Democrats are familiar enough with Trump to be able to rate him, while just 44% are able to rate Kasich. Cruz, as another example, is familiar to 69% of Democrats.

To control for familiarity, I recalculated the net favorable scores among only those individuals who are familiar with the candidates; those results appear in the accompanying table. Trump's score doesn't change much, -70 to -74, since most Democrats are familiar with him to begin with. But others' scores change more. Cruz's net favorable score, for example, goes from -37 among all Democrats to -54 among just those who are familiar with him, and Huckabee's goes from -34 to -52.

At any rate, the rank order is generally the same. Trump's -74 net favorable rating among Democrats who know him is still the lowest of any GOP candidate, way below Cruz's -54 and Huckabee's -52 among Democrats who know them. And among independents who are familiar with him, Trump's net favorable score is -30, significantly more negative than Bush's -18 or Huckabee's -11.

It is not at all clear that Republican caucus and primary voters who will end up voting for Trump in those contests think about who would have the best chance of winning in a general election or care about what non-Republican voters will think about him in November -- were he to win their party's nomination. In fact, the personality traits that are responsible for Trump's highly negative image among those who identify with the other party are most likely part and parcel of what makes him attractive to GOP voters. Further, in today's polarized political environment, winning a general election may depend more on mobilizing existing voters who already support the candidate than attempting to make inroads into those who identify with the opposite party.

It's possible that Trump's image could become more positive during a general election campaign -- although we've seen no evidence of change so far. A look at our data from last July, the first month in which we tracked the candidates, shows that Trump's net favorable rating among Democrats was -68, essentially the same as it is now. In other words, after months and months of exposure to Trump throughout the fall, Democrats' views of him have not shown any signs of getting better (nor worse, for that matter), suggesting a lower probability that their views of the entertainer and businessman would change significantly after more months of exposure to him this year.