Jeb has not really shot himself down. He did not have the charisma imagined by the media & Republican headquarters' personnel. He did not have the ability to deal with the unexpected. He simply never had the position of strength, never the image with anyone outside the media & Republican headquarters' personnel, that some of those folk had imagined.
He is not likely to gain a stature that he was imagined to have, that he never had to begin with.
I honestly do not wish the man ill. I cannot support him for President--both because of his policies, as well as his demonstrated inability to handle a real challenge.
In addition, Jeb is badly out of practice as a candidate, having last been on the ballot well more than a decade ago in 2002 when he ran for reelection as governor of Florida. Over-funded and staffed by well-paid loyalists, Jeb's campaign lacks nimbleness and is blind to its central need to re-introduce Jeb to the country and to identify the country's problems and Jeb's answers for them.
Thus, as a Presidential candidate, Jeb comes across as stale and cloddish, with nothing pertinent to say to the conservative GOP base except insults and disrespectful comments. His new catch phrase -- the "right to rise" -- sounds like an ad tag for a brand of yeast. Worse, for millions of Americans, a campaign pitch about the poor and immigrants' "right to rise" suggests scanting the effort of the struggling middle class to keep what they have.
Worse, Jeb's description of Mexican illegal immigration as an "act of love" and that "anchor babies" refers to Asians but not Hispanics suggest a combination of crude pandering and utter disregard of the costs and burdens of illegal immigration. Jeb's marriage to a Mexican and deep appreciation for Mexico and its culture put him at odds with the fear of many Americans that their country is at risk of being overwhelmed by excessive immigration and a lack of assimilation.