If Jeb does run, he may face Hillary Clinton on the Democratic side. Now, a "Clinton vs. Bush" contest doesn't exactly thrill many people who are looking for perhaps a little more variety (and a little less dynasty) in our presidential choices, but it is indeed worth contemplating at this point, at least if Jeb is serious about running.
Most people today just use "go the way of the Whig Party" as an amusing way to say "disappear as a national political party." But a truer parallel to history would be to ask the question: "Will today's Republicans revert back to being the Whig Party?" Or, perhaps: "Will the Tea Party eventually go the way of the Whig Party?"