Michael Kinsley memorably quipped, “A gaffe is when a politician tells the truth — some obvious truth he isn’t supposed to say.” Sen. Kamala Harris (D‑CA) recently committed a gaffe when she admitted that Sen. Bernie Sanders’ (I‑VT) Medicare for All proposal would oust close to 200 million Americans from their existing health insurance arrangements, a prospect that causes public support for Medicare for All to plummet from 56 percent to 37 percent. Harris thus helpfully illustrated why Sanders’ proposal is, to be kind, so pie-in-the-sky bonkers that it would never pass Congress.

Indeed, the only way Medicare for All could happen is if free-market advocates focus all their fire on that proposal rather than the incremental and thus more politically feasible steps toward a single-payer system that Medicare for All supporters are offering. I am speaking in particular about the various proposals they are offering to create a so-called “public option,” usually by expanding eligibility for Medicare or Medicaid.

In 2009 and 2010, the Left used a public option as a stalking horse for ObamaCare. The Left demanded a public option and lured free-market advocates into focusing their fire on that proposal, only to have congressional Democrats drop the idea and pass ObamaCare as some sort of moderate or compromise measure.

That went so well—or let’s just say, the bill passed—the Left is now using Medicare for All as a new stalking horse for the old stalking horse. Savvy Democrats are hoping that if Sanders whips up the base over Medicare for All, congressional Democrats will be able to pass a public option (e.g., a Medicare/​Medicaid “buy-in,” or “Medicare X”) again as some sort of moderate or compromise measure.

A public option is merely a slower and more politically feasible way to achieve the destruction of private health insurance than what Sen. Harris proposes. Supporters say they merely seek a level playing field where a public option may compete with private insurance. Of course, a level playing field between government and private insurers is impossible. It has never happened. It will never happen. It cannot happen.

If you want to know how serious Democrats are about letting private insurance compete with a public option on a level playing field, look at how they are treating a free-market alternative to ObamaCare: short-term, limited duration health insurance. The Obama administration prohibited short-term plans from offering crucial consumer protections; it crippled them by unilaterally decreeing that enrollees in such plans must face medical underwriting more often than federal law requires. Democrats have decried the Trump administration’s decision to allow short-term plans to shield sick enrollees from medical underwriting, and are trying to *rescind* those consumer protections because they are not provided by the government. Senate Democrats voted to kick patients with preexisting conditions out of their short-term plans, leaving those patients to face up to 12 months of expensive medical bills with no insurance coverage whatsoever. Illinois Democrats passed a similar law over Gov. Bruce Rauner’s (R) veto. California Democrats completely banned short-term plans — and thereby gave real teeth to ObamaCare’s 10-month rationing period.

How is any of that a “level playing field”?

Supporters of a public option don’t want open competition. They don’t want to give you just one more choice. They want to destroy private insurance. They want a public option to be your only option. They want you to have no choice.

In the end, a public option is even more dangerous than the Sanders bill. Unlike Sanders’ frontal assault, a public option could actually deliver Medicare for All.