Well past time to set the record straight on the Carter presidency

[MichMan]

81. President Clinton was not "required" to sign it.

From the Wikipedia source you referenced

Before sending it to the United States Senate, Clinton added two side agreements, the North American Agreement on Labor Cooperation (NAALC) and the North American Agreement on Environmental Cooperation (NAAEC), to protect workers and the environment, and to also allay the concerns of many House members.

Clinton signed it into law on December 8, 1993; the agreement went into effect on January 1, 1994.[27][28] At the signing ceremony, Clinton recognized four individuals for their efforts in accomplishing the historic trade deal: Vice President Al Gore, Chairwoman of the Council of Economic Advisers Laura Tyson, Director of the National Economic Council Robert Rubin, and Republican Congressman David Dreier.[29] Clinton also stated that "NAFTA means jobs. American jobs, and good-paying American jobs. If I didn't believe that, I wouldn't support this agreement."

It was ratified by the House and the Senate with a lot of broad support. Bush started it, true, but if President Clinton had refused to sign it, it would not have ever gone into effect.