Trump is so far ahead in the South Carolina polls he doesn't have to worry about his debate performance last night.
This picture at the link says a million words
It becomes more and more obvious as the primary season goes on that I am right about why Trump is in the race, and that is to prevent another Bush from being president. Whether he and the Clintons cut a deal, he cut a deal with the Democratic Party, or he just decided to fuck things up on his own, it is very obvious his role is as a ratfucker.
Trump let his inner Democrat show through a few times last night, especially with regard to the Iraq War and 9/11. Perhaps out of deference to the death of Antonin Scalia, Trump stopped just short of going after Jeb and his role in the 2000 election sham.
I wouldn't be one bit surprised if Trump does go there in a future debate.
As for the audience boos, one shouldn't read too much into it. One could even argue informal polls like Drudge's are more important.
The "outsiders," meaning Trump and Sanders, are dominating.
Of course, Sanders will fizzle out long before Trump does.