“When I was a boy I was told that anybody could become President. I’m beginning to believe it.”

Source: píseň Mother

Source: The Boy Crisis (2018), pp. 231

Speech in Indianapolis, Indiana (26 September 1952)
Often misquoted as "In America, anybody can be president. That's one of the risks you take."

Source: Black Heart

Source: Out of Sight, Out of Time

Speech before Congress (April 4, 1917), Congressional Record—Senate, April 4, 1917, 224–225.
Context: Mr. President, I had supposed until recently that it was the duty of senators and representatives in Congress to vote and act according to their convictions on all public matters that came before them for consideration and decision. Quite another doctrine has recently been promulgated by certain newspapers, which unfortunately seems to have found considerable support elsewhere, and that is the doctrine of “standing back of the President” without inquiring whether the President is right or wrong.
For myself, I have never subscribed to that doctrine and never shall. I shall support the President in the measures he proposes when I believe them to be right. I shall oppose measures proposed by the President when I believe them to be wrong.

Jonkers, Gert (2003). "Friendly homosexual fashion designer likes dogs but finds fashionable men terribly unsexy" http://www.buttmagazine.com/Issues/7_Jacobs.html buttmagazine.com (accessed April 19, 2007)
On his perfect customer

Presidential declaration speech, Ted Cruz declaration speech: Full transcript http://www.independent.co.uk/news/world/americas/ted-cruz-declaration-speech-full-transcript-10128614.html, Independant.co.uk (March 23, 2015)
2010s

As quoted in "Concerns Beyond Just Where the Wild Things Are" by Patricia Cohen in The New York Times (9 September 2008)