McALLEN - Barack Obama's statements that he would consider renegotiating the decade-old North American Free Trade Agreement are drawing criticism from Rio Grande Valley business leaders. The treaty, which removed most trade and investment barriers among the United States, Mexico and Canada, has quickly turned into a point of contention between Obama, the presumptive Democratic presidential nominee, and his Republican counterpart, John McCain, whose pro-free trade stance calls for even more NAFTA-like trade blocs - specifically with Colombia and South Korea. Obama has routinely denounced the treaty as a deal that "put special interests over workers' interests," as he said...