More than six months after the launch of her campaign, Kamala Harris has finally defined her health-care position. Now she wants Medicare Advantage for All, in partnership with the oft-vilified insurance companies that progressives hope to crowd out with Medicare for All. It sounds like a great compromise … except for one very large point:

Sen. Kamala Harris on Monday unveiled a plan to achieve universal coverage by growing Medicare with the help of private insurers, an effort that splits the difference with her chief Democratic presidential rivals and finally equips the California Democrat with her own signature health proposal ahead of this week’s debates.

“Medicare works,” Harris writes in a Medium essay posted Monday morning. “Now, let’s expand it to all Americans and give everyone access to comprehensive health care.” …

Harris’ new plan breaks with her rivals who occupy the opposite poles of the debate by effectively proposing “Medicare Advantage for all” — permitting private insurers to continue selling plans, akin to the two-decade-old offshoot of Medicare — in addition to letting Americans immediately buy into the traditional Medicare program and adding new benefits, like more mental health services. As a result, Americans would be able to choose between the public plan or certified private Medicare plans. Harris also says she’ll immediately enroll newborns and the uninsured, an effort to quickly get to universal coverage.

Is this a Solomonic splitting of the progressive baby, or evidence of chronic ignorance about the rest of the American electorate? Harris has come down on both sides of the question of private health insurance as her campaign had struggled to produce a reform plan that fits the progressive moment. On some occasions, Harris has backed Medicare for All and the end of private health insurance, only to reverse her endorsement of the latter while not quite backing the former.

So what’s the one very large fly in this ointment? Telling 150 million Americans they have to lose their insurance to get on Medicare:

“We will allow private insurers to offer Medicare plans as part of this system that adhere to strict Medicare requirements on costs and benefits,” writes Harris. “Medicare will set the rules of the road for these plans, including price and quality, and private insurance companies will play by those rules, not the other way around.”

But this means she would still jettison employer-sponsored health plans, which now cover more than 150 million Americans.

Whatever problems exist in the individual-plan market, the employer-provided insurance markets tend to work well. People are generally happy with their coverage and insurer performance, mainly because insurers can’t afford to lose the big accounts by chintzing out on one employee. There are going to be very few people who will cheer losing their employer-based coverage to get thrown into a governmental bureaucracy like Medicare, especially outside of the Democratic activists Harris is attempting to court with this plan.

Let’s also remember a couple of important aspects of Medicare Advantage. It exists because, frankly, Medicare is insufficient. It covers gaps in the underlying plan, which is why it’s so popular. Also, don’t forget that the Obama administration raided Medicare Advantage in ObamaCare in order to make it look deficit-neutral in its first ten years, arguing that Medicare Advantage was just another way that insurers had to exploit consumers and the government.

So it’s rather amusing to see this endorsement of Harris’ plan:

Harris plan got the nod of approval from former Health and Human Services Secretary Kathleen Sebelius, who helped implement the Affordable Care Act under former President Barack Obama.

“This plan builds on the progress we made in the Affordable Care Act and expands upon its promise of universal coverage through a sensible expansion of the popular Medicare system,” she said. “To get all Americans covered by health insurance, where cost is not a barrier, we need innovative ideas like this. Senator Harris’ plan is a smart way to get to Medicare for All where all individuals and employers can transition smoothly into a system that covers everyone.”

Perhaps most people have short memories about Democratic hostility toward Medicare Advantage. They shouldn’t. Once a transition to Medicare for All takes place, it will be extraordinarily easy to shut out the insurers. Democrats nearly did so ten years ago with ObamaCare’s changes to Medicare at that point.

On the whole, this doesn’t look like a promising compromise for Harris, not even in the Democratic primary. Progressives aren’t pushing Medicare for All because they love the program — they’re doing so because they hate the insurers. The ten-year ramp-up to mandated government control will be too slow for their tastes. For everyone else, Harris’ hilarious contention that this can be accomplished without raising taxes on the middle class will make it look ridiculous to anyone who does math — and knows the Constitution:

Another notable difference in the Harris plan to the Sanders bill — she would not increase taxes on the middle class. Under the Sanders plan, households making above $29,000 would be taxed an additional 4% income-based premium. Harris raises the threshold, exempting households making below $100,000, with an even higher income threshold for families living in high-cost areas. A progressive tax system would be designed for households making over $100,000.

Ahem. Harris wants to create a different kind of federal taxation for “high-cost areas”? The federal government cannot charge different tax rates for people living in different parts of the country. Article I, Section 8 of the Constitution expressly declares, emphasis mine:

The Congress shall have Power To lay and collect Taxes, Duties, Imposts and Excises, to pay the Debts and provide for the common Defence and general Welfare of the United States; but all Duties, Imposts and Excises shall be uniform throughout the United States

Just as there can’t be a federal tax bracket for California or New York, the government can’t impose a tax rate on wealthy areas that differ from poorer districts. If Harris could do this, she could then manipulate the tax system to benefit blue districts and precincts while punishing red ones, the very corruption the founders wanted to prohibit with this clause.

Harris’ proposal is a disaster borne of her own incoherence on health-care reform. Good luck selling this to the 150 million Americans who still count themselves lucky not to have had to deal with ObamaCare, let alone Medicare.