It is early October, by this point in 2012 Rick Perry and Herman Cain looked like candidates that could secure the nomination. Bush is slightly ahead in picking endorsements, which are going to make all the difference when it comes to meeting voters and bringing in donors. Bush could slip behind for sure, but dropping out this early, when there are other candidates who are going to have to go first, is foolish.
This is the media trying to make the race "more exciting" by pretending someone has to drop out every so often. Most candidates are going to be smart enough to see through it.
vs.
At this point four years ago.
Notice the big glaring difference between Mitt Romney's stable status as the consensus candidate in the low-mid 20s vs Jeb Bush dwindling into nothing in high single digits? There's pretty significant differences between these two cycles, and Jeb Bush polling around where Ron Paul 2012 was polling and in fifth(!) place is a pretty major one from Romney trading between first and close second while not having his actual numbers really budge from their position of strength.
