“It’s useless to try to hold a person to anything he says while he is madly in love, drunk, or running for office” is a jocular quotation that has been credited to many people. The quotation has been cited in print since at least 1957, when it was written by Olin Miller (1894-1981), who wrote for a newspaper in Thomaston, Georgia. Miller’s syndicated daily feature entitled “Dixie Dewdrops” appeared in many other newspapers, and his lines were frequently quoted by others. 
 
The quotation has been mostly frequently (since the 1990s) credited to American actress Shirley MacLaine, but there is no evidence that she said it before Olin Miller.
   
 
Old Fulton NY Newspapers
21 March 1957, The Castilian & Northern Allegany Observer (Castille, NY), “Grist & Grits” by Olin Miller, Thomaston, Ga., pg. 2, col. 1:
It’s useless to try to hold a person to anything he says while he is madly in love, drunk, or running for office.
   
Google News Archive
29 May 1957, Wilmington (NC) Morning Star, pg. 6, col. 7:
THREE OCCASIONS
It is useless to try to hold a person to anything he says while he is madly in love, drunk, or running for office. — Jackson (Miss.) State Times.
 
3 September 1957, Aberdeen (SD) American-News, “Earl Wilson in South America,” pg. 4, col. 5:
EARL’S PEARLS…It’s useless to hold a man to anything he says while he’s in love, drunk or running for office.
 
Google Books
The Numismatist
Volume 86
1973
Pg. 1000:
It is useless to try to hold a person to anything he says while he’s madly in love, drunk or running for office. (B. Birdsong, quoted in The Readers Digest].
 
Google News Archive
13 October 1976, Ocala (FL) Star-Banner, “Smile,” pg. 1, col. 1:
It’s useless to try to hold a person to anything he says while he is madly in love, drunk or running for office,
   
Google Books
14,000 Quips & Quotes:
For Speakers, Writers, Editors, Preachers, and Teachers
By E. C. McKenzie
Grand Rapids, MI: Baker Book House
1990, ©1980
Pg. 154:
It’s useless to try to hold some people to anything they say while they’re madly in love, drunk, or running for office.
 
Google Books
Oxford Dictionary of Humorous Quotations
Edited by Gyles Brandreth
New York, NY: Oxford University Press
2013
Pg. 8:
It’s useless to hold a person to anything he says while he’s in love, drunk or running for office.
Shirley MacLaine 1934– American actress