Trump had his worst debate by far. He called three people liars (George W., Jeb, and Ted Cruz), called Cruz a nasty man, said he would use profanity if he felt like it, and generally just went on about how great he is and how he's going to:
start winning again. We don't win anymore.
bring back jobs from China and from Mexico.
rebuild the military so big and powerful nobody is going to mess with us. Nobody.
make great trade deals. We don't make good deals anymore.
take care of our vets. Our vets are going to be taken care of.
build a wall along the border. We're going to make Mexico pay for it.
repeal and replace ObamaCare. It's gone.
in other words the same speech we've heard 1,000 times. When he was asked by the moderator how he was going to achieve some of his promises, he launched into speech mode and gave no details. Contrast his answers with Rubio, Bush, or even Kasich. They give specific answers to these questions.
His attacks on Jeb are not going to play well in South Carolina. They like George W. there. Trump's lead was in the mid 20's last week, he is now down to a 20 point lead. I expect that to shrink, but probably not enough for him to lose the state. Interesting that everywhere he goes his leads shrink.