<Li> Not have been president already, even in a provisional capacity (see Succession below). </Li> <P> The ban on any sort of presidential re-election dates back to the aftermath of the Porfiriato and the end of the Mexican Revolution . It is so entrenched in Mexican politics that it has remained in place even as it was relaxed for other offices . In 2014, the constitution was amended to allow Deputies and Senators to run for a second consecutive term . Previously, Deputies and Senators were barred from successive re-election . However, the president remained barred from re-election, even if it is nonsuccessive . </P> <P> The presidential term was set at four years from 1821 to 1934, and has been set at six years since 1934 . The president is elected by direct, popular, universal suffrage . Whoever wins a simple plurality of the national vote is elected; there is no runoff election . </P> <P> The most recent former President, Felipe Calderón, won with 36.38% of the votes in the 2006 general election, finishing only 0.56 percent above his nearest rival, Andrés Manuel López Obrador (who contested the official results). Former President Vicente Fox was elected with a plurality of 43% of the popular vote, Ernesto Zedillo won 48% of the vote, and his predecessor Carlos Salinas won with a majority of 50% . The current president, Enrique Peña Nieto won 38% of the popular vote . </P>

How long can you be president in mexico