The main reason Jeb was the early frontrunner in the Republican sweepstakes was his last name. Despite the fact that we are nominally a democracy, Americans still harbor a secret hankering for royal dynasties.
But that hankering has its limits. After eight years of Bill Clinton, the American public was nostalgic for the decent, patrician George H.W. Bush, so they elected his namesake. But even after eight years of Obama, the American public is not nostalgic for W. So, Jeb is paying the price.
Jeb also had other problems right from the start. First, that eminently punchable face. And second, he was way too liberal on immigration. You don't win over American voters by pandering to the Mexican electorate.
Early on, Jeb's own parents saw him, not W, as the carrier of the family flame. This, despite W being the older brother. If anyone knows which the smarter sibling is, it would be the parents. But the Presidency is not an SAT test; it's simply not enough to have a high IQ.
Character counts -- bad character, that is. Jeb is simply too nice a guy for this arena. He is an intelligent beta male without the instincts for battle that a Trump or Cruz or Rubio have. It's almost as if Jeb was coddled too much as a kid, and never developed the kind of spiky armor that more feral kids tend to develop. For instance, Jeb obviously defers to his wife. (Do you think Trump does that?)
Ted Cruz had a great line about the moderators in the last debate, but he was wrong about one thing: a debate IS a cage match. And if you don't have the instincts of a pro wrestler, you're simply not going to survive the Wrestlemania Summer Slam, or Wrestlemania Survivor Series. The debates were just slightly higher IQ versions of those extravaganzas. Both sets of audiences certainly want the same thing: blood, whether physical or metaphorical.
Jeb simply isn't bloodthirsty enough. When someone shoots an arrow at Jeb, instead of shooting back, he just looks down in astonishment at the feathers sticking out of his stomach. He spent much of the debates looking like a mole that's been dragged from its protected underground lair, and, blinking in the bright sunlight, has no idea how to defend itself against the coyotes which surround it.
And, nice guys finish, if not last, at best sixth in a field of ten.
In the last couple debates, Jeb has tried to be a little more combative, because his advisors have told him he needs to be. But you can tell, it's really just not in his nature.
But while it's hard to blame Jeb for being too nice, it's a little easier to criticize the vague sense of entitlement that always surrounded his campaign. Jeb's pedigree is that of card-carrying member of the East Coast WASP establishment who used to run the country. You can see it in the way he talks about the illegal immigrants, with the sort of noblesse oblige that WASPs of good character were expected to show when speaking of the less fortunate.
But it's a little as if Jeb is living in a time warp, and doesn't quite realize that the world has changed. The nexus of power has long since shifted from the WASPs to the Jews, and while most of the candidates were eagerly declaring their allegiance to Israel in hopes of some of that Adelson and Singer money, Bush seemed to think that if he carried himself like Clark Clifford, he'd inherit the Presidency.
It just doesn't work that way anymore.