In a Parliamentary debate with the Conservative MP, John Pakington (May 31, 1866). Hansard, vol 183, col 1592. Pakington was referring to Footnote 3 to Chapter 7 of Mill's "Considerations on Representative Government".
Misquoted as "I never meant to say that the Conservatives are generally stupid. I meant to say that stupid people are generally Conservative. I believe that is so obviously and universally admitted a principle that I hardly think any gentleman will deny it." in "Life of John Stuart Mill" (1889) by W. L. Courtney, p. 147.
This seems to have become paraphrased as "Conservatives are not necessarily stupid, but most stupid people are conservatives." which was a variant published in Quotations for Our Time (1978), edited by Laurence J. Peter.
Crossfire debate on censorship (1986)
“I know you're not a stupid person, so why would you ask such a stunningly stupid question?”
Source: Novels, Squeeze Me (2020), Chapter 28
Interview with Alex Altman of Time Magazine, in Alex Altman, " Why Ted Cruz Thinks the Media Gets Conservatism Wrong http://swampland.time.com/2013/08/08/why-ted-cruz-thinks-the-media-gets-conservatism-wrong/#ixzz2cnxPPCOQ", Time Magazine (August 8, 2013).
2010s
Originally column published as "No-Respect Politics" in The Washington Post (26 July 2002) https://www.washingtonpost.com/archive/opinions/2002/07/26/no-respect-politics/f7f00171-0731-4fd8-9c07-7fae9ecb725f/
Source: 2010s, 2013, Things That Matter: Three Decades of Passions, Pastimes and Politics (2013), Chapter 3 : Pride and Prejudices, "The Central Axiom of Partisan Politics".
First speech as leader at the Conservative Party conference(1991) http://www.johnmajor.co.uk/page863.html
Source: First speech as leader at the Conservative Party conference (1991) http://www.johnmajor.co.uk/page863.html
Letter to Eileen Danniheisser (1953), quoted in Albert Einstein: Creator and Rebel by Banesh Hoffman (1973), p. 261 http://books.google.com/books?id=sdDaAAAAMAAJ&q=%22think+with+fear%22#search_anchor. The exact date, or the name of his correspondent, is not given in the snippet of the book available online, but the quote appears after the letter to the Queen of Belgium from 12 January 1953, and is prefaced by "Nine months later, in words that recall the beliefs of an early atomic speculator, the Roman poet Lucretius, Einstein had written to an inquirer", followed by the quote. The name "Eileen Danniheisser" is given in Time: Volume 144, where it is mentioned in the snippets here http://books.google.com/books?id=JDAnAQAAIAAJ&q=%22obsessive+thoughts%22#search_anchor and here http://books.google.com/books?id=JDAnAQAAIAAJ&q=%22think+with+fear%22#search_anchor that she had written Einstein "about her obsessive thoughts of death as a child".
1950s
“I felt the question was stupid so I didn't answer.”
Source: Novels, Spitting off Tall Buildings (1996), Ch.6 - p.33 [Page numbers per the Canongate Books Ltd. 2001 UK paperback edition]
"The Brooklyn Divines." Brooklyn Union (Brooklyn, NY), 1883.
