It's not just a matter of this Bush being even more liberal than George W. Bush, although that's a big factor; it's also a matter of the Presidency not being a hereditary position. There is absolutely no need to establish any family, let alone the Bush family, as a dynasty.
However much the GOP may want it to be.
I have an intense dislike for the budding (or not-so-budding, as the case may be) aristocracy in this country. The Bush family is a prime example of it, an extremely rich family with members holding (or "having held") all kinds of high government offices and a plethora of connections inside government. It's like a less-communist version of the Kennedy family, and I don't think I need to spell out what I think of them.
Trump will not be the GOP nominee. That much is certain; Jeb Bush is the GOP leadership's favorite dog in this hunt, and I would be greatly surprised if he failed of nomination. It's much more likely that we face (as I predicted earlier) another Bush-vs-Clinton race in this election, and regardless of who we get we will not see Obamacare overturned or immigration curtailed or any of a thousand other things that need to be done in order to pull this country out of the quagmire Obama has led us into.
Jeb Bush will nominate Supreme Court justices who are no better than Justice Roberts, the deciding vote in the cases that have left us stuck with Obamacare. His justices would be better than Hillary's only by degree, and on the crucial matters they would vote with the aristocracy rather than with the law and the Constitution. Exactly the way his brother's nominees do.
There is no remedy in not voting; that much is certain. But I do not have to vote for whatever shit sandwich the GOP presents, and if Jeb Bush is their guy, he won't be mine.