Lyndon B. Johnson (1908–1973) American politician, 36th president of the United States (in office from 1963 to 1969)
1960s, Voting Rights Act signing speech (1965)
Context: If you do this, then you will find, as others have found before you, that the vote is the most powerful instrument ever devised by man for breaking down injustice and destroying the terrible walls which imprison men because they are different from other men.