A campaighn to change the American constitution to allow Arnold Schwarzenegger to run for the White House has begun, as the film star ended his first year as governor of California on Wednesday.Fans of the Austrian-born actor have swamped the airwaves of his adopted state with television advertisements calling for an end to the ban on citizens of the US born abroad becoming president.The move has in theory been launched on behalf of all naturalised Americans but the name of the group behind it, ‘Amend for Arnold’, leaves little doubt as to its main thrust.‘‘You cannot choose the land of your birth,’’ its principal backer, Lissa Morgenthaler-Jones, says in the advertisements. ‘‘You can choose the land you love.’’ The advertisement says: ‘‘Twelve million people have chosen America,’’ a reference to the country’s naturalised citizens. ‘‘Help us to amend the constitution. Help us to amend for Arnold.’’Schwarzenegger, 57, has not explicitly supported the initiative but has hinted that he might consider standing for the presidency if so allowed by the constitution.Amending America’s basic law is a major undertaking. The Senate and the House of Representatives must both approve the change by a two thirds majority and 38 of the nation’s 50 states must ratify the move. While there is no direct link between the action film star and the ‘‘Amend for Arnold’’ group, Morgenthaler-Jones has been an enthusiastic donor and volunteer working for his new career.