With all the grace and felicity of a falling piano, Hillary Clinton flattened Bernie Sanders in South Carolina.

It wasn't even close. Clinton demolished Sanders, obliterating him by nearly 50 points, 73.5 percent to 26 percent. This was far and away the most dominating primary or caucus victory for any candidate of either party in this 2016 race.

But (with a Clinton, there are always buts), in a telling sign of just how warmed-over her campaign has become, Clinton beat Sanders by a 93-point margin among black voters over 60… but only a 13-point margin among black voters under 30, according to exit polls. There's something happening here, and what it is is embarrassingly self-evident: Young people are not moved, touched, or inspired by Hillary Clinton.

As much of a good hatewatch as the GOP might get from the Clinton show, however, her asphalt-paving advance toward the nomination holds up an ugly mirror to the GOP. Republicans envious of Clinton's clear path and ready patronage badly want to ensure that their party, too, nominates the most unapologetically conventional candidate possible. A fresh face and cunning candidate like Marco Rubio was sure to enjoy built-in appeal at a moment when many voters don't care if you lack a strong record of prudential judgment forged through experience in statecraft. But for the established Republican leadership, Rubio's personality is just the whipped cream and the caramel drizzle atop the frappucino of his policy program — namely, an utterly unrepentant embrace of the most stereotypical Republican talking points ever to be typed into a PowerPoint presentation.

The Clintonian character of the GOP's brightest new star has some smart Republicans shuddering. Rubio was always the Republican who campaigned most like Clinton, playing a national game, not a local one, on the back of tightly scripted and lethally competent debate performances (New Hampshire notwithstanding). But, as with Clinton, that affect was the effect of his establishmentarianism. He has always done his best, like Clinton, to present himself as a general election candidate, as early and often as possible. That's because the way he and she want to govern is sharply at odds with a huge slice of their respective parties' constituencies.

Alas, Democrats are in denial about this. Instead of sharing a cold chill of recognition, they're high-fiving each other over GIFs of Donald Trump in various stages of Rubio-induced discombobulation. They think they can co-opt Sanders voters in a way Republicans no longer can mollify their base. And they think that'll give them the win in November.

It's easy and strangely reassuring to try to make sense of the GOP primary by tossing out crazy scenarios — the third-party crackup, the brokered convention, the team of plainclothes ex-special ops mercenaries of Polish descent stuffing Trump in the back of a van. It's harder, but actually far more plausible, to envision a bench-clearing brawl this March from which one candidate emerges ready to unload on Clinton without missing a beat. The true outcome will probably wind up somewhere in the middle of those two extremes, and in that case, Clinton could turn out to be more similar to Rubio — in an unflattering way — than Democrats are willing to imagine.

Like Rubio, she will have to double down on mechanical proficiency, trying to lug along an uncertain base. Like Rubio, she will have to present "same old same old" as the greatest thing since sliced bread, acting as if the slightest and most cosmetic of updates represent bold leaps into a new era.

But unlike Rubio, Clinton is an old campaigner and not a good one. She blows leads, she gets boring, she disconnects. All the Republicans have to do is prevent a total meltdown in Cleveland to be competitive.

Still, there's something incredibly sinister about an election cycle wherein the strongest simultaneous popular insurgencies in living memory might culminate in both parties nominating the candidates who are least representative of the insurgents. The frustration and fury on the right and the left, especially among politically active younger voters, is not a fad. Even on the left, it cannot just be flattered and scattered. If Clinton faces a ticket that can offer even one significant policy connecting up with today's widespread anger and responding to it, polling suggests that once again she will follow a string of convincing victories with eventual defeat.