 The identity document in Mexico serves also as the voting card, so all citizens are automatically registered for all elections; that is, no pre-registration is necessary for every election.All elections are direct; that is, no electoral college is constituted for any of the elections at the federal, state or municipal level.Only when an incumbent president is absolutely absent (either through resignation, impeachment or death), the Congress of the Union constitutes itself acts as an electoral college to elect an interim president by absolute majority.