The most compelling quote in Lizza's piece comes not from a politician or strategist or commentator but from an old college friend of Paul's—closer to a normal human being, in other words. Back in 2010, GQ reported an entertaining moment at Baylor when Paul and a co-conspirator snatched a friend and made her pray to "Aqua Buddha." Lizza tracked down the source, Kristy Ditzler, and got her to go on the record. It turns out she was appalled by the way her anecdote was turned into an attack on Paul, but she was still uneasy about how Paul seemed to be whitewashing his college days:

"The only reason I felt like speaking up was that I was a little bit irked by him making himself out to be all about God and country and all about conservative values, because he was clearly not promoting that when I knew him,” Ditzler said. “I mean, we all change, we all have a past. If he’s changed, why can’t he just say that he’s changed?”

Flip-flopping is always a problem for a candidate, but everyone has changed their view on something at some point. It's especially tricky for Paul because his brand is speaking truth to power, bravely speaking out against the consensus, and truly believing in what he says. If he's willing to change positions now, is he all that different from the average politician? And if so, why bother with an occasionally prickly first-term senator? Been there, done that.

One way around this question is the view that Jesse Benton, a friend and aide to both Pauls, espouses to Lizza: Rand hasn't changed, it's just that he's now in a different position and is working through what it means to apply his principles. “If Ron were President, he would have had to govern like Rand," Benton said. "Ron is much more of a purist about non-intervention, and that’s fine, but in many ways Ron’s foreign policy can exist only in an academic sense. It’s just not possible for the United States to be non-interventionist. It’s not much of a difference on principle, but a much bigger difference in practice.”

That might be true, but it doesn't account for the material change in the younger Paul's position on, say, ISIS. And it doesn't help him build distance from his father's foreign-policy views, which make the Republican establishment and many voters particularly uneasy.

Another tack is simply to pretend that the younger Paul doesn't believe the stuff he's saying now. Paul fans told The Daily Beast's Olivia Nuzzi earlier this month that the senator was just playing a political game and suggested he didn't really mean it—which doesn't do much for the true-believer reputation.

Meanwhile, Ron Paul's past continues to haunt his son. Take the racist newsletters published in the former representative's name. Rand Paul bristles at being connected with fringe groups, but he also seemed happy to use the conspiracy theorist Alex Jones's radio show as a platform during his Senate race. He's had his own links to questionable characters, like the former neo-Confederate radio host Jack Hunter, a Paul aide until he was forced to resign when his past as the "Southern Avenger" came to light. Nor does it help that Rand Paul's mother Carol, Ron's wife, told Lizza, “Everybody that calls him wants to argue about their differences. They don’t really have differences. They might have fractional differences about how to do things, but the press always want to make it into some kind of story that isn’t there.”