Vietnam War was "winnable"?

Here I read reference again to the Vietnam War as having been "winnable," had only President Johnson not "held back" the military from the all-out effort that would have done it, and which silent dissenters in the military allegedly thought crucial at the time. Granted, modest warfare can kill more people, more painfully than aggressive warfare--e.g. starvation vs. occupation--and I suppose at the limit of that continuum you get deterrence and/or extortion with no war waging at all. But are the folks who talk about Vietnam winnability actually speaking of any different point on that continuum than where MacNamara, the carpet bombers and the search-and-destroy school actually placed the U.S.? I have to doubt it's a moral victory they're talking about winning.