The children of political candidates are useful adornments in campaign literature and ads, and when they are older, as character witnesses on the campaign trail.

Rarely are they used as attack dogs, let alone armed with shameless talking points to try to dampen the rise of an inspirational political rival. But nothing is beneath Bill and Hillary Clinton. So they trotted out their daughter, Chelsea, to warn about the dastardly designs that Bernie Sanders has for ending Medicare as we know it.

It’s part of a hammer-and-tongs assault that should feel familiar to Republicans. It turns out that becoming the target of Medicare demagoguery isn’t just for Newt Gingrich or Paul Ryan anymore. No one has released an ad of Bernie Sanders pushing a senior citizen over a cliff yet, but if the Vermont senator continues his rise, just give it a couple of more weeks.

Chelsea Clinton charged that Sanders “wants to dismantle ObamaCare, dismantle the [Children’s Health Insurance Program], dismantle Medicare and dismantle private insurance.” For those keeping score at home, that’s a lot of dismantling. Chelsea said she worried — the chain of reasoning was left fuzzy — that Sanders would somehow give Republicans “permission” to go back to the pre-ObamaCare era and “strip millions and millions and millions of people of their health insurance.”

Frightened yet? What Sanders is proposing is so-called Medicare for all, a universal, single-payer health-care program that has been the goal of progressives for decades. For this he is being savaged by a Hillary Clinton, who in the early 1990s famously immolated herself in a doomed fight for her version of universal coverage.

The gravamen of her case against Sanders is that he is a socialist — and an enemy of the welfare state. He is advocating a further step in the Democratic crusade to expand the social safety net — and is a dangerous radical because of it. He is a threat to all that has been achieved by the left — because he wants to achieve more.

None of this makes much sense, especially on progressive terms. The dynamic of progressivism is never to rest, and always to ask for more. Hillary Clinton’s implicit contention is that after a century of progressive agitation for the steady expansion of government, the ultimate has been achieved via ObamaCare and now only needs some tinkering.

Obamacare is a massive government intrusion into American health care, but it’s not the universal coverage that the likes of Teddy Kennedy made a generational cause. At enormous cost and disruption, it pushed the portion of the population with insurance coverage up from roughly 85 percent to about 90. As Sanders points out, that still leaves 30 million people uninsured.

Hillary wants to identify herself with President Barack Obama and reactivate his coalition, but her anti-Sanders tack is hardly inspiring. To put it in Obama 2008 argot, Hillary is touting the fierce urgency of ... maintaining the status quo. Her supporters are fired up and ready ... to adopt a prudent incrementalism. She fervently believes that, Yes, we can ... modestly adjust American health care around the edges.

This is not to say that the Sanders approach isn’t vulnerable to attack. It would be enormously expensive. By the sunny estimate provided by the Sanders campaign, it would cost $14 trillion over 10 years. It would require far-reaching tax increases, including — as even Sanders admits — on the middle class. To achieve cost savings, it would inevitably rely on price controls and rationing.

Sanders makes his plan sound like a cost-free exercise that would be a boon to American families. Sanders insists that they would save $3,800 to $5,100 annually on health care, seeing and raising Barack Obama’s (implausible and since discredited) promise that ObamaCare would save families $2,500. Hillary wants to portray Bernie Sanders as some kind of wrecking ball, when he is firmly in the progressive tradition of fervency in the cause of the endless aggrandizement of the state.

Rich Lowry is the editor of The National Review.