“When you fight for a desperate cause and have good reasons to fight, you usually win.”

Source: #‎DefundPlannedParenthood‬: https://www.tedcruz.org/l/defund-planned-parenthood/ On Facebook September 29, 2015.

Disturbing the Universe (1979)
Context: A good cause can become bad if we fight for it with means that are indiscriminately murderous. A bad cause can become good if enough people fight for it in a spirit of comradeship and self-sacrifice. In the end it is how you fight, as much as why you fight, that makes your cause good or bad. <!-- Pt. 1, Ch. 4

The Second World War, Volume I : The Gathering Storm (1948) Chapter 19 (Prague, Albania, and the Polish Guarantee).
Post-war years (1945–1955)

Depa Billipa and Mace Windu, p. 313
Shatterpoint (2004)

General Robert E. Lee, Part IV, CH 5: Longsteet, p.361
The Killer Angels (1974)

This quote is widely attributed to Margaret Thatcher on various websites, and also appears in a number of books, including The Concise Columbia Dictionary of Quotations, Columbia University Press (1989), ed. Robert Andrews, p. 320 : ISBN 0231069901. 9780231069908 , but without any further source information such as date, location or any other context.
One valid Thatcher quote which may be the basis for the version above appears in the Second Carlton Lecture http://www.margaretthatcher.org/document/105799 (‘Why Democracy Will Last’), delivered at the Carlton Club, London (November 26, 1984) : Mr. Chairman, each generation has to stand up for democracy. It can’t take anything for granted and may have to fight fundamental battles anew. You know that marvellous quotation from Goethe : ‘That which thy fathers bequeathed thee / Earn it anew if thou would possess it.’
Thatcher also expressed this thought in a Speech to Atlantic Bridge (May 14, 2003) http://www.margaretthatcher.org/document/111266, delivered at the St. Regis Hotel, New York City : My friends, every generation has to fight anew the battle for liberty.
Disputed

"Mean People Fail", November 2014