TRUMP EFFECT!!...GO TRUMP!
Even those who don't like Trump have to give The Donald credit for smoking out Jeb Bush. Imagine if Trump had NOT entered the race. At this point, instead of Jeb on the verge of pulling out, he would be in the position of consolidation as the other candidates split the vote. He would now be gloating about how the other candidates had their say but now the "rational" thing to do would be to support him. Like Mitt Romney in 2012, he would be the Establishment fallback apparent nominee...and then LOSE in the general election.