One of our major neo-liberal economists is wondering where NAFTA went wrong. Brad DeLong had a PDF wondering why with all the export driven growth in Mexico conditions for the people haven't improved. He looks at China and corruption and lack of education and training and the U.S. subsidized corn production. I would also look at the tax structure leading to growing inequality and insufficient infrastructure and social support services as well.
There has been a serious debate among economists that no country really practices "free trade" and that the fastest growing economies over the long term made smarter choices on which industries to protect and grow. This is controversial given the American economic tradition of following Adam Smith.
This growing doubt about the benefits of liberal trade policies by Democratic economists has political implications. Here is a short blog essay by a corporativist but it doesn't capture the complexities of the issue.
The 2008 Democratic candidates on trade agreements.
Ben Smith notes the Democrats seem to be more willing to intervene in the economy than Bill Clinton did.