Thousands of Mexican farmers, some riding tractors and herding cows, flooded the capital Thursday to demand government protection against cheap U.S. imports.Trade barriers under the North American Free Trade Agreement, or NAFTA, were lifted in January, opening Mexico for the first time to tariff-free U.S. exports of traditional food like corn and beans. Mexican farmers complain the government of President Felipe Calderón is not doing enough to protect them against highly subsidized U.S. goods. Protesters are demanding Mexico renegotiate the treaty with the United States to maintain protections for corn and beans. Long lines of slow-moving tractors choked highways from ….Read More