Different times, different candidates.
8/31/12 leader Perry 29% was toast after debate memory lapses.
10/19/12 leader Cain - 37% was toast after Bimbo eruptions.
Trump has nothing in news of extra-marital shenanigans. As famous as Trump has been for 30 years, believe me Enquirer would have sold lots of copies if they had discovered Trump scandals.
At this time only way Trump falls by the way side is if he commits a serious gaffe during debates.