Lizza asks Jonathan Gruber, a key architect of Romneycare and Obamacare:

Gruber broke down the A.C.A. “winners” and “losers” for me. About eighty per cent of Americans are more or less left alone by the health-care act—largely people who have health insurance through their employers. About fourteen per cent of Americans are clear winners: they are currently uninsured and will have access to an affordable insurance policy under the A.C.A.

But much of the current controversy involves the six per cent of Americans who buy their own health care on the individual market, which the A.C.A. has dramatically reformed. Gruber argued that half of these people (three per cent of all Americans) will have little change to their polices. “They have to buy new plans, but they will be pretty similar to what they had before,” he said. “It will essentially be relabeling.”

The other half, however, also three per cent of the population, will have to buy a new product that complies with the A.C.A.’s more stringent requirements for individual plans. A significant portion of these roughly nine million Americans will be forced to buy a new insurance policy with higher premiums than they currently pay. The primary reason for the increased cost is that the A.C.A. bans any plan that would require a people who get sick to pay medical fees greater than six thousand dollars per year. In other words, this was a deliberate policy decision that the White House and Congress made to raise the quality—and thus the premiums—of insurance policies at the bottom end of the individual market.

Avik Roy, a staunch Obamacare critic who has cherry-picked facts in the past, claims that roughly a third of Americans will lose their current coverage. He bases this on quotes from a June 2010 edition (pdf) of the Federal Register, which publishes notices from government agencies:

“The Departments’ mid-range estimate is that 66 percent of small employer plans and 45 percent of large employer plans will relinquish their grandfather status by the end of 2013,” wrote the administration on page 34552. All in all, more than half of employer-sponsored plans will lose their “grandfather status” and get canceled. According to the Congressional Budget Office, 156 million Americans—more than half the population—was covered by employer-sponsored insurance in 2013.

Another 25 million people, according to the CBO, have “nongroup and other” forms of insurance; that is to say, they participate in the market for individually-purchased insurance. In this market, the administration projected that “40 to 67 percent” of individually-purchased plans would lose their Obamacare-sanctioned “grandfather status” and get canceled, solely due to the fact that there is a high turnover of participants and insurance arrangements in this market. (Plans purchased after March 23, 2010 do not benefit from the “grandfather” clause.) The real turnover rate would be higher, because plans can lose their grandfather status for a number of other reasons.

How many people are exposed to these problems? 60 percent of Americans have private-sector health insurance—precisely the number that Jay Carney dismissed. As to the number of people facing cancellations, 51 percent of the employer-based market plus 53.5 percent of the non-group market (the middle of the administration’s range) amounts to 93 million Americans.