The entire concept of free trade as a beneficial scheme is based on century's old concepts of comparitive and absolute advantage. Those concepts were developed in a time where distance itself was a barrier to trade, adding enormous costs to trade and itself creating comparitive advantage for some countries (it's difficult to ship peaches on a sail boat from China, I'm sure you'll agree). Technology has erased any comparitive advatange in almost every industry you can describe; even surgeries will be done via internet connection in the near future.
In sectors in which labor can't be outsourced, technology is largely employed to do away with human labor at all. I stayed at an Embassy Suites this weekend, they had self-check-in, I printed my airplane boarding pass from a terminal in the lobby of the hotel, I served myself coke from a fountain...&c. How many human beings would have done those jobs 15 years ago? And, in the absense of a manufacturing sector, where do you suppose the unskilled get jobs? Supposing we could all become college educated, what becomes of the value of a college education? Unrestrained free trade, if allowed to go to it's final conclusion, would have nations of PhDs who can't get jobs. And how do you suppose all of those people will pay for ever increasing education requirements given decreasing wages and increasing living costs?
In the past, free trade was seen as a way of creating a delegation of labor for the world, now it's seen as a way of seeking the cheapest labor possible. It is a global race to the bottom for all but the wealthiest among us. And, there's no doubt that free trade is good for them; a middle class (even upper middle class) person, and certainly poor people, cannot make a case that free trade is beneficial for them (but can only puke back political B. S. that they've been told by the media and the major parties).
To say that CPI doesn't tell the whole story is ignoring the fact that defenders of free trade tell us that the reduction that we see in our wages is offset (or even more-than-offset) by cheaper goods. The numbers don't pan that out at all -- which is of course why you have to suggest that in the absense of supposedly cheap imports the CPI would have grown all the same (a reasonable person would assume that U. S. manufacturers would have become more adept as time went on, and that new technology would have made them ever more effecient). Of course, even if CPI had gone up for the last 25 years (as it has), then in the absense of the free movement of capital (while labor is forced to remain static due to immigration laws), then wages would have been forced to increase.
The only reason manufacturers can afford to see wages slip in the major consumer capitals is that they are driving their costs of production ever lower through exploitation of a never ending supply of cheap labor around the world.
Funny, too, that people would claim merchantilism (or, as you call it, protectionism) to be a troublesome economic construct when that very system built America as an economic powerhouse!