Reporters have been feeding on healthcare.gov, the most visible interface the public will have with President Obama’s signature health-care initiative. Technological errors on seemingly every Web page have confounded would-be insurance buyers. The Obama administration’s early reassurances that things would work relatively soon after launch turned out to be self-defeating spin. Experts blame a variety of design flaws.

This line from Tuesday’s Post, though, reflects a fundamental mistake the administration made:

U.S. Chief Technology Officer Todd Park has said that the government expected HealthCare.gov to draw 50,000 to 60,000 simultaneous users but that the site was overwhelmed by up to five times as many users in the first week.

This fact represents a terrible failure to accept the daunting reality the government faced leading up to the planned Oct. 1 rollout of healthcare.gov.

There were some reasons to think the launch of healthcare.gov might not result in crushing interest. When Massachusetts rolled out its Connector Web site, a similar system the state launched on its own before the national health-care law came into effect, a variety of early technical problems didn’t matter as much, because the flood of visits and enrollments came as coverage deadlines approached, not at launch. That gave the state time to fix up the Connector before lots of people had to depend on it.

The Obama administration should not have expected anything like the Massachusetts experience, for a variety of reasons. At the top: Obamacare has regularly dominated American politics for half a decade. A Pew Research Center poll just found that more than half of visitors to the site already have insurance. Maybe they were helping friends. Or maybe they wanted to check out an accessible manifestation of a reform that has until now existed mainly as a concept, long over-stuffed with both expectation and criticism. Conservative leaders, meanwhile, have been eager to focus public attention on any problems with the law’s implementation.

The government needed to launch a site that could both handle a huge volume of visitors — from the uninsured, from their friends, from the merely curious — and provide them a reasonably smooth experience on Day One. It didn’t have Massachusetts’s room for error, a point that should have been plastered over every wall in front of every programmer and manager. And if the government really couldn’t deliver, it needed to anticipate and preemptively manage the instantaneous frustration of millions. Lots of people were going to visit and make up their minds about healthcare.gov on Day One — particularly on Day One. The government’s health-care mavens shouldn’t just have expected high Web traffic, they should have expected that high interest would mean that people’s impressions about the site would be formed early-on, impressions that would be hard to dispel later. Instead, they behaved as though launching a critically flawed and critically important Web site without warning would not be a big problem.

If, after failing to put together a workable site, pushing back healthcare.gov’s launch date wasn’t an option, the Obama administration could still have come to its senses and orchestrated some kind of soft launch weeks and weeks ago. It could have emphasized well before Oct. 1 that health-care insurance marketplaces were to open for phone, paper and online applicants, but that the site is still in progress. This approach would have produced a public-relations fiasco. But the Obama administration has a worse one on its hands now. Given that the new health-insurance system relies on high volumes of uninsured people signing up, at least a soft launch would have discouraged fewer people from returning to the site later. And it would have been, you know, honest.