Writing in part based on a story that appeared in the Wall Street Journal, Forbes’s Avik Roy says the following:

At the end of the day, for all of the rhetoric and promises about what Obamacare would achieve, the health law’s most ardent supporters have stuck to their guns because of one thing: coverage expansion. But new data suggests that Obamacare may fail even to achieve this goal. Instead of expanding coverage to those without it, Obamacare is replacing the pre-existing market for private insurance. Surveys from insurers and other industry players indicate that as few as 11 percent of those on Obamacare’s exchanges were previously uninsured. If these trends continue, the probability increases that Obamacare will eventually get repealed.

It turns out that more than half (52 percent) of those who didn’t sign up for the Affordable Care Act’s coverage cited “affordability” as their biggest complaint with the exchanges’ plan offerings. (“Wasn’t that supposed to be the point behind the Affordable Care Act?” quips HotAir.com’s Ed Morrissey.)

Mr. Roy is a sober, serious health-care expert who is always worth listening to. Which is why I want to quote his concluding section in full:

I, along with most observers, have viewed as doubtful the likelihood that Obamacare ever gets repealed. Even if Republicans manage to regain the White House and the Senate by 2017, there will be tens of millions of people on Obamacare-based coverage by then. Prior to the website fiasco of October, the Congressional Budget Office projected that 34 million Americans would be enrolled in either the exchanges or the Medicaid expansion in 2017. It would be politically impossible to disrupt the coverage of 34 million people.

But what if the number is far less than 34 million? What if it’s only 5 million? Such an epic fail would seem far-fetched, but then again, so did the dismal performance of Obamacare to date. For 2014, the CBO has projected that 14 million previously uninsured Americans would gain coverage under the law. With about ten weeks left in this year’s enrollment period, we’re looking at a coverage expansion of less than a million.

Remember also that as many as 100 million previously insured Americans will endure higher premiums—and higher taxes—under Obamacare. The political constituency of the newly insured could be dwarfed by the political constituency of those harmed by the law. If that turns out to be the case, President Obama’s signature legislation may not be long for this world.

If so, it would sink the Obama presidency, both in real time and in the eyes of history. Which is precisely what ought to occur.