With the polls tightening in Iowa and voting both there and in New Hampshire just a few weeks away, the Kumbaya feeling in the Democratic primary is gone. In particular, the Hillary Clinton camp has evidently decided it's time to go on offense against independent Sen. Bernie Sanders, lest 2016 start feeling like 2008 all over again.

Predictably, one line of attack is on Sanders' record on gun control, which certainly has its blemishes. Another, though, makes far less sense, particularly in a Democratic primary: Clinton is lambasting Sanders' proposal for a universal, single-payer health care system. And she's doing it in a pretty dishonest way.

"His plan would take Medicare and Medicaid and the Children's Health Insurance Program and the Affordable Care Act health care insurance and private employer health insurance and he would take that all together and send health insurance to the states, turning over your and my health insurance to governors," Clinton said. "We had enough of a fight to get to the Affordable Care Act. So I don’t want to rip it up and start over."

Clinton's daughter Chelsea got in on the act, too, in an even worse manner, claiming that Sanders wants to "dismantle Obamacare." She said: "I worry if we give Republicans Democratic permission to do that, we'll go back to an era, before we had the Affordable Care Act, that would strip millions and millions and millions of people off their health insurance."

This is mostly rank nonsense. A single-payer system, like it does in many other countries, would cover everybody, period. To say otherwise is either willfully misunderstanding how it would work or simple scaremongering.

Hillary Clinton, jumping on a line in an old Sanders bill that says his plan would be administered by the states, is attempting to tie him to the failure of many Republican governors to embrace Obamacare's Medicaid expansion, which has resulted in millions of people being denied health insurance. But that's very different from single-payer: Sure, Republican governors could maybe try to weasel out of whatever a President Sanders had in mind, but to think he would design a plan that governors could just ignore is silly. (For the record, Sanders' camp emphatically says the plan would apply to everyone.)

Chelsea Clinton's attack is even worse, making it sound as if Sanders is like the Republicans who call to "repeal and replace" Obamacare without actually drafting a "replace" plan. As former Obama administration adviser David Axelrod said on CNN last night, "Bernie Sanders is proposing single-payer, universal healthcare. You can hardly say he is trying to take health care away from anyone or retreat from Obamacare. He's trying to exceed it. And so it's not really an honest attack."

But Hillary Clinton doubled down on her daughter's words on Wednesday, saying on "Good Morning America" that Sanders would "take everything we currently know as health care, Medicare, Medicaid, the CHIP Program, private insurance, now of the Affordable Care Act, and roll it together.” As she knows, since she is well-versed in health care policy, that's a feature, not a bug of single-payer; the alphabet soup of insurance programs is one of things that makes American health care so confusing and inefficient. Instead of attacking the idea on the merits, she's choosing to make it seem as if Sanders has a callous disregard for people losing health insurance.

This actually isn't the first time Clinton has broken out this line of criticism. In a December debate, she also used it, while parroting a ridiculous analysis claiming that Sanders' proposals would cost $18 trillion to $20 trillion. (That analysis estimated the costs of his ideas without accounting for the savings or benefits.) But now, in the heat of an ever-tightening campaign, her broadsides have taken on new meaning and urgency.

There are certainly legitimate ways to question whether single-payer is feasible right now, particularly since the Republicans are going to be able to hold on the House for the foreseeable future. Or maybe Clinton thinks, like President Barack Obama did, that switching to single-payer would be too disruptive or too difficult considering the system we already have in place.

But she isn't saying that. Instead, she's sliming Sanders with the accusation that he wants to take health insurance away from people. It's a garbage attack, and makes even less sense considering that she's going to need Sanders' supporters come November when she (as is still very likely) becomes the Democratic nominee. (Democrats, incidentally, really like single-payer, as do independents.)