The single-payer, Canadian-style health care system has always been the one health care alternative in Congress that the average American can understand without getting a headache. But it has long been considered a nonstarter. Things may be changing. Now it even has a bumper sticker — I saw one on a Honda — and will soon have its own TV commercials which will, let us pray, not be as terminally insulting to the intelligence as those we’ve seen from the Health Insurance Association of America. On the other hand, if it’s infantile enough, maybe it will convince Americans that single payer is safely mainstream.

And yes, it is possible to imagine a realistic political scenario by which a single-payer system could pass Congress and be signed by the president. Farfetched?

Begin by recognizing that there were from the beginning a lot of closet single payers in Congress and elsewhere who looked to other solutions simply because the plan — even with 100 supporters in Congress — seemed such a lost cause. Then imagine how many have been silently converted to this group in the last year when they considered the studies, saw all the holes in the alternatives and took one look at the staggering complexity of the president’s plan.

They can disagree, but it is difficult to imagine, for instance, that Sens. Daniel Patrick Moynihan and Jay Rockefeller aren’t potential single payers. I’d even include Mrs. Clinton, who more than a year ago dismissed single payer not necessarily as unwise but as not “doable.” Anybody who has spent as much time as she has immersed in the complexities and the politics of the health care issue cannot but be attracted to the blessed simplicity of a Canadian-style system.

Then imagine that the American Medical Association comes to its senses and recognizes that single payer is the best hope of preserving patient choice and physician independence. The American College of Surgeons surprised everybody last February by endorsing a single-payer plan. If the surgeons — the grandees of the profession — can swallow it, how long before it becomes a stampede?

Still, you’d have the deep pockets and lobbying might of business community and of the health care industry to overcome. Single payer still looks like a loser. But what if the business community deserts? Single payer is, after all, the best guarantee there is against employer mandates. Is there a corporation president in the nation who wouldn’t think he’d died and gone to heaven if he could unload his health care costs — not to mention all the paperwork and fuss — on the government? All they’d need is assurance that business wouldn’t be hit with an unfair share of the taxes necessary to fund a single-payer plan. This is doable enough, considering that single payer is the most demonstrably effective way of getting a handle on health care costs.

Anyway, single payer may still be a long shot, chiefly because it is stuck with the label of being the most radical of the alternatives. This is silly, of course, because when in the last 300 years has anything radical ever snuck across the border from Canada? Canadians, whatever their virtues, make the world’s worst radicals.

Robert Reno writes for Newsday.