While in the planning stages, NAFTA was a much-debated topic in all three countries. President George Bush (who played a major role in the drafting of the agreement) and President Bill Clinton (who helped promote and implement NAFTA) were two of the agreement's biggest proponents in the United States, while Texan billionaire Ross Perot and conservative politician Pat Buchanan spoke out against it. Many thought that NAFTA would result in a loss of American jobs as companies moved south to take advantage of cheap labor and deregulated markets. This would lead to increased labor exploitation and human rights abuses. Others argued that it would lead to the development of the troubled Mexican economy and that all three countries would benefit from increased trade. Environmentalists were concerned that an increase in trade would lead to further development of industries along the Rio Grande, causing additional pollution problems to an already-endangered area. NAFTA advocates, on the other hand, argued that with the implementation of the agreement it would be much easier to regulate and monitor pollution along the border.