“All Presidents start out pretending to run a crusade but after a couple of years they find they are running something less heroic and much more intractable: namely, the presidency.”

Source: The Running Man

Post-Presidency, DNC address (2004)

Speaking on January 7, 1930, when asked what made him think he was "worth more than the President of the United States," as quoted in "Yanks Refuse Ruth's Demand For $100,000; Star Asks That Figure On 3-Year Contract or $85,000 and No Exhibitions" http://www.mediafire.com/view/mbioqflkxsmp4cb/Vidmer%2C%20Richards.%20Yanks%20Refuse%20Ruth's%20Demand%20for%20a%20Hundred%20Thousand.%20The%20New%20York%20Herald%20Tribune.%20Wednesday%2C%20January%208%2C%201930..jpg by Richards Vidmer, in The New York Herald Tribune (January 8, 1930); also quoted in part—i.e. "The President gets a four-year contract; I'm only asking for three"—later that month in a syndicated story http://www.google.com/search?q=%22babe+ruth%22+%22four-year+contract+I%27m+only+asking%22++Claire+NEA&hl=en&gbv=2&oq=%22babe+ruth%22+%22four-year+contract+I%27m+only+asking%22++Claire+NEA&gs_l=heirloom-serp.12...14955.25097.0.27212.14.12.1.0.0.0.183.1124.3j6.9.0....0...1ac.1.34.heirloom-serp..14.0.0.VHm9Bp_6pGo by NEA sportswriter Claire Burcky.
<blockquote><center>^✱Immediately following is the virtually ubiquitous but almost certainly apocryphal "I had a better year..." variation; in addition, see related contemporaneous quotes from Brian Bell, Herbert Hoover, Albert Keane, Reuters and Will Rogers in Quotes about Ruth.</center></blockquote>
Context: Say, if I hadn't been sick last summer, I'd have broken hell out of that home run record! Besides, the President gets a four-year contract. I'm only asking for three.✱</sup

Senator McCain's announcement speech for his 2008 presidential bid https://en.wikipedia.org/wiki/John_McCain_presidential_campaign,_2008 (25 April 2007)
Full text of the speech can be found here on The New York Times http://www.nytimes.com/2007/04/25/us/politics/26mccain_text.html
2000s, 2007

2000s, Mother of All Mothers (September 2004)

Statement to reporters (2 August 1927); cited in Bartlett's Famous Quotations, 16th ed. (1992).
1920s

Presidential campaign (April 12, 2015 – 2016), First presidential debate (September 26, 2016)

ABC News TV interview, 2009-10-14. AFP http://www.google.com/hostednews/afp/article/ALeqM5gm7wRjrtKmZ_faPv0UVCgiOClxhg
Secretary of State (2009–2013)

Katastroika (1988)