For an individual with a job in a textile factory, there may indeed be displacement. Yet over the centuries, our economy has "lost" millions of jobs. Weavers no longer ply their trade in front of a hand loom, threshers don't stride through the golden fields of wheat with their scythes, and wheelwrights and blacksmiths have lost their livelihoods to the horseless carriage. Yet unemployment has not shot up to 100%; over time, we've found jobs to replace all of these specialties.
Perhaps someone will protest that we lost those jobs to technology, rather than trade, but what's the difference between competing with a Chinese laborer, and competing with a machine? Either one can cause distressing temporary dislocation, but both of them make us more productive, boosting our lifestyle (and, thankfully, the lifestyle of the Chinese laborer).
Now, I feel this needs a qualifier. While in general I agree with her; if the US gave up a manufacturing job and gained a tech-sector job, then both US and China would benefit. However, not every vacated job in the last 100 years was replaced by a fitter, smarter job that provided the employee with enhanced happiness. How many manufacturing jobs, given this lose one - gain one scenario, have been replaced by high-stress jobs in real estate, or in mutual funds? Jobs that, for some, might provide a paycheck and nothing more. How many lost manufacturing jobs are replaced by volatile jobs at companies that fire and rehire with a libertarian-loved reckless disregard for anything but the bottom line?
Here's my bottom line: until we can successfully educate the American people to a point where they all take productive, stable jobs in technically demanding fields, we will need manufacturing jobs to keep unemployment down.
More on this to come.