During the 1993 battle over the North American Free Trade Agreement, the proposal's promoters' most politically effective argument was that NAFTA would keep Mexicans out of the United States. As political writer Elizabeth Drew later observed, "Anti-immigration was a sub-theme used, usually sotto voce, by the treaty's supporters."
The voce was not always sotto. "We don't want a huge flow of illegal immigrants into the United States from Mexico," said former President Gerald Ford, speaking at one of then-President Bill Clinton's pro-NAFTA rallies. "If you defeat NAFTA, you have to share the responsibility for increased immigration into the United States, where they want jobs that are presently being held by Americans."