I find it incredibly troubling that one has to be a great speaker to become President of the United States. You have to be able to articulate a message and communicate once elected, yes, but not everyone is Ronald Reagan.
Jeb Bush is where he is because people are angry right now, probably more angry than they were under Jimmy Carter. Bush is telling people to be happy and optimistic, and in the end I think they will be, but right now they are angry and the outsiders are tapping into that anger. But Jeb Bush is the anti-Obama in this election; he has a conservative agenda, a conservative record, and he is an honest guy. But people are fed up and don't realize that Bush draws the starkest contrast not just on the stump, but in having an actual record, with the Democrats.
Republicans are angry with Bush because he's running for President despite being the brother of a recently failed GOP President. All the apologia for W you can muster doesn't change the public verdict on Bush 43, which still stands. Republicans of ALL stripes get this, and they don't want to lose in 2016. They view Jeb's candidacy as self-indulgent on Jeb's part, and on the part of the entire Bush Family, and, quite frankly, I can't see a reason why any partisan Republican, whether they be liberal, moderate, or conservative, should view Jeb's candidacy in any other light.