The number of Vice-Presidents in the 20th century that became President because of something happened to the President like President John F. Kennedy and his Vice-President Lyndon Johnson; and Richard Nixon and his Vice-President Gerald Ford. With partisan politics strongly dividing Congress, the Vice-President works as the tie-breaking vote in the Senate. Both situations reflect the greater importance of the Vice President´s office (as the President's responsibilities increased in the 20th century, those of the Vice President also increased).