I had a lot of sympathy for George Stephanopoulos Sunday when he faced the president in a one-on-one interview. This can be an uncomfortable spot to be in, especially when your interview subject is likely to be difficult. And Obama, it turns out, was indeed difficult, if not downright testy. Stephanopoulos tried hard in the interview, first zooming in on the president’s campaign pledge (repeated many times since) that the middle class would, on his watch, be subject to no tax increase. The president still held to that pledge during his talk with Stephanopoulos, but then launched into a diversionary discussion of health care affordability—a crucial point we at Campaign Desk have been hammering away at.

When Stephanopoulos asked whether the president agreed with other Democrats that the draft bill from the Senate Finance Committee—a.k.a. the “Baucus bill”—calls for a big middle-class tax increase, Obama said he did not agree.

I think that they were concerned about whether or not this was actually affordable. If you’re saying to people, ‘you’ve got to get health insurance,’ but they can’t actually afford it and they have to pay a penalty if they don’t get it, then that’s a pretty big burden on middle-class families. That’s a concern I share—making sure that this is affordable.

Stephanopoulos let the president off the hook on what an affordable policy would look like, and then gave him the upper hand. But, hey, it’s hard to say “no” to the president, and the journalist allowed the politician to air his bread-and-butter talking points—all that stuff about the bill being deficit-neutral, people having more security, and the uninsured getting affordable coverage.

Since the president didn’t say it, though, we will: “Affordable” coverage for many will probably mean skimpy benefits and sky-high deductibles—insurance products companies are just itching to sell to millions of new customers.

Stephanopoulos came back, however, for a counterpunch. “You were against the individual mandate,” he said to the president, who replied that, yes, he was. “How is that not a tax?” Stephanopoulos asked. The president then tried to make a case that everyone in the country was paying higher premiums because people aren’t able to afford health insurance and are thus relying on emergency-room resources for treatment—resulting in what Obama called “uncompensated care.” (That’s jargon for hospitals not getting paid by people who don’t have money.) “You and I are both paying $900 on average—our families—in higher premiums because of uncompensated care,” the president told his interviewer. But did he mean by that that some middle-class people were already paying a tax and that the tax would simply be shifted to other middle-class people?

The president still insisted that the tax penalties people would have to pay for not buying insurance—as much as $3,800 for a family with an income of $66,150—was not, in fact, a tax increase, even though Stephanopoulos said otherwise. Obama kept trying to convince his audience that a tax penalty was not a tax increase by equating it to the personal responsibility to buy health insurance:

For us to say that you’ve got to take a responsibility to get health insurance is absolutely not a tax increase. What it’s saying is, is that we’re not going to have other people carrying your burdens for you anymore than the fact that right now everybody in America, just about, has to get auto insurance. Nobody considers that a tax increase.

Stephanopoulos tried a comeback, but got a scolding instead. “But, George, you—you can’t just make up that language and decide that that’s called a tax increase.”

Finally, Stephanopoulos got to the official meaning of a “tax” by—what else?—reading the definition from Merriam-Webster’s Dictionary. The dictionary, Stephanopoulos noted, said a “tax” was “a charge, usually of money, imposed by authority on persons or property for public purposes.” The definition said nothing about responsibility to buy insurance. Obama countered:

George, the fact that you look up Merriam’s dictionary, the definition of tax increase, indicates to me that you’re stretching a little bit right now. Otherwise, you wouldn’t have gone to the dictionary to check on the definition.

Stephanopoulos said he wanted to check for himself and came back with the next punch. “But your critics say it is a tax increase.” To which the president replied: “My critics say everything is a tax increase. Look, we can have a legitimate debate about whether or not we’re going to have an individual mandate or not….”

Stephanopoulos tried once again: “But you reject that it’s a tax increase?”

Trudy Lieberman is a fellow at the Center for Advancing Health and a longtime contributing editor to the Columbia Journalism Review. She is the lead writer for The Second Opinion, CJR’s healthcare desk, which is part of our United States Project on the coverage of politics and policy. Follow her on Twitter @Trudy_Lieberman.