Xlinton was the one that got it passed, through a Democrat-controlled Congress in 1993. Blaming Republicans for helping it pass is partly fair, but overblown. This really was an Socialist-Co-Opted piece of legislation masquerading as something it was not.
It was never about the U.S. economy. It was about ending the Cold-War trade barriers which defended America's industrial sinecure. Xlinton was the one who implemented a number of concessions to Mexico facilitating the relocation of U.S. capital, and undermined U.S. regulatory positions.
At the time I was a reluctant supporter of NAFTA, or at least I thought I understood the reasoning. In my mind it was a move to counter Asia labor advantage and to counter EU creating a market as Large as the US market. I saw two economic super powers on the horizon EU lead my France/Germany, not friendly to US interests and Pacific Rim lead by Japan. (I did not foresee China's rise as a economic super power back in 92) So I figured NAFTA was an attempt to expand the NA market and counter EU and Japanese economic muscle.
But it has not turned out that way, employers have fled to Asia anyway, the Mexicans are as corrupt as always and still exporting poor criminal class so I say NAFTA was a failure and more of the same ain't gonna get it.