The second half of his administration was marked by his conflict with Andrés Manuel López Obrador, then Mexico City's Mayor. The PAN and the Fox administration unsuccessfully attempted to remove López Obrador from office and to prevent him from participating in the 2006 presidential elections. The Fox administration also became embroiled with diplomatic conflicts with Venezuela and Bolivia after supporting the creation of the Free Trade Area of the Americas, which was opposed by those two countries. His last year in office oversaw the controversial 2006 elections, where the PAN candidate Felipe Calderón was declared winner by a very narrow margin over his opponent López Obrador, who claimed that the elections were rigged and refused to recognize the results, calling for protests across the country. In the same year, the southern state of Oaxaca was the scene of a teacher's strike which culminated into protests and violent clashes asking for the resignation of governor Ulises Ruiz Ortiz.