The worst aspect of Hillary Clinton's primary campaign so far has been how she has treaded on the very idea of social insurance for brief tactical advantage.

Her opponent Bernie Sanders has come out for higher taxes to fund things like single-payer health insurance. In response the Clinton campaign has attacked him from the right as a tax-and-spend liberal who will dismantle Medicare and reduce middle-class incomes — instead of, say, arguing the idea is good but politically infeasible.

The flagrant dishonesty of some of these attacks briefly put pro-Clinton pundits on their back feet. But after Sanders released a brief campaign sketch of his single-payer plan, they regrouped and began an assault against both it and his financial reform plan. Their arguments were at best blinkered and at worst seriously misleading, and missed the political forest for the policy weeds.

Let's roll the tape. Ezra Klein, founder of Vox and well-known for his wonk brand, was first out of the gate with a long piece brutally savaging Sanders' single-payer plan as an unrealistic, "irresponsible," "puppies and rainbows" proposal. New York Times columnist Paul Krugman approvingly cited this argument, piling on that its funding relied on a "magic asterisk" — a reference to his takedowns of various conservative budgets which slash taxes to the bone while not explaining how they will avoid increasing the budget deficit — concluding that single-payer was a "distraction from the real issues."

Yet Klein's takedown of single-payer committed some rather shocking errors of fact. He argues that Sanders plan is misleading about the biggest source of single-payer savings, which, he seemed to imply, is the denial of coverage to patients. But as Seth Ackerman carefully explains in extant universal systems most of the savings comes from governments leaning on providers, and Klein (among several other errors) is squirrelly indeed on this crucial point:

By this (admittedly partial) reckoning, more than 87 percent of the taxpayer savings generated by France’s "Saying No Apparatus" (as it were) came out of the pockets of Abbott’s shareholders. Only 13 percent came out of the patient's. Yet Klein’s article systematically obscures the distinction between the two, while making it seem that Sanders’s plan, out of some kind of populist irresponsibility, chose to forego the main sources of real-world single-payer cost containment. In fact, the reverse is true: It was Klein who was doing that. [Jacobin]

This blows a largish hole in the political case against Sanders' plan, which leaned on the probable backlash from those who couldn't get their homeopathy treatments or whatever covered by single-payer.

Krugman ignored this point, however, and moved on to financial reform, wherein he took offense at being described by David Dayen as a Clinton "minion," writing two posts about how Sanders' theory of financial reform was nonsense. But because he did not link to the actual argument in question, it was easy to miss that he paved over quite a lot of complexity. Krugman portrayed the Sanders plan as all about reinstating Glass-Steagall and breaking up the biggest banks, ignoring credible arguments on the Volcker Rule and Section 716 of Dodd-Frank. At the very least, Sanders' argument about attacking banks' overwhelming political power deserves serious consideration. But nope, "every serious progressive policy expert on either health care or financial reform who has weighed in on the primary seems to lean Hillary."

It's worth browsing Clinton's health care page to see how she proposes to cover the roughly 30 million people who are still uninsured. Just kidding. There's almost nothing.

So after all that, it's a bit rich to see Krugman sigh theatrically about the vile abuse he's getting from Sanders supporters, and prop himself up, along with Klein and Jonathans Cohn and Chait, as the archetypal wonk who always makes decisions strictly on the policy merits. It reads very much like any other political partisan attempting to mask his preference as the neutral, correct choice. He did the same routine in 2008, when he also supported Clinton, and it was obnoxious then too.

Indeed, as Glenn Greenwald notes, the whole routine is a pitch-perfect imitation of the centrist Very Serious Person swatting down the unhinged left-wing critic, down to the exact language, that Krugman himself has been railing against for years and years.

At any rate, aside from the all this bickering, the major political error on display here is the belief that having a fully worked-out policy proposal is of bedrock importance. As Josh Marshall observes, "Pundits and political obsessives tend to get distracted by process and policy literalism." But as Steve Randy Waldman aptly puts it, "Policy is a third-order pile of bullsh-t," a product and not a mover of political and moral tectonic plates.

Details matter when it comes to writing a bill (and Sanders' single-payer proposal could certainly stand a lot of fleshing out), but that is years away at best — neither Clinton nor Sanders is likely to get anything through a Republican Congress. Right now pushing hard for the basic facts of single-payer — namely, that it will cover everyone and will cost a ton of tax money — is important and valuable, not least because it serves as a decent opening bid for future negotiations and a political anchor to keep the debate focused in a good place. To preemptively give up policy terrain to get a detailed plan at this stage is not remotely serious, politically or historically.