“The supreme issue, involving all others, is the encroachment of the powerful few upon the rights of the many.”

Speech in Paisley (6 February 1920), quoted in Speeches by The Earl of Oxford and Asquith, K.G. (London: Hutchinson & Co., 1927), p. 265
Later life

Poem on opponents of the GPL’s sharing requirements, as quoted in "Stallman joins the Internet, talks net neutrality, patents and more" at NetworkWorld (23 March 2015)
2010s

From his speech given on 28 November 1960 at laying the foundation-stone of the building of the Law Institute of India, in: p. 14
Presidents of India, 1950-2003

1880s, Personal Memoirs of General U. S. Grant (1885)
Context: Slavery was an institution that required unusual guarantees for its security wherever it existed; and in a country like ours where the larger portion of it was free territory inhabited by an intelligent and well-to-do population, the people would naturally have but little sympathy with demands upon them for its protection. Hence the people of the South were dependent upon keeping control of the general government to secure the perpetuation of their favorite institution. They were enabled to maintain this control long after the States where slavery existed had ceased to have the controlling power, through the assistance they received from odd men here and there throughout the Northern States. They saw their power waning, and this led them to encroach upon the prerogatives and independence of the Northern States by enacting such laws as the Fugitive Slave Law. By this law every Northern man was obliged, when properly summoned, to turn out and help apprehend the runaway slave of a Southern man. Northern marshals became slave-catchers, and Northern courts had to contribute to the support and protection of the institution.

Page 4
The Challenge to Liberty (1934)

Telegram, turning down a party invitation from Mr. and Mrs. Robert F. Kennedy (13 June 1962)

Inaugural Address (4 March 1845)
Context: By the theory of our Government majorities rule, but this right is not an arbitrary or unlimited one. It is a right to be exercised in subordination to the Constitution and in conformity to it. One great object of the Constitution was to restrain majorities from oppressing minorities or encroaching upon their just rights. Minorities have a right to appeal to the Constitution as a shield against such oppression.

8.Paul Samuelson Knows How to Disagree Agreeably.
Ten Ways to Know Paul A. Samuelson (2006)