U. S. President Ronald Reagan (1811-2004) wrote twice in his diary that his fellow Republicans were “rabbits” (i.e., someone who is weak and who runs away) when he needed “tigers” (i.e., someone who is strong and who is willing to fight). In his diary for December 7, 1982, Reagan wrote:
 
“We had rabbits when we needed tigers.”
 
In his diary for April 5, 1983, Reagan wrote:
 
“We have rabbits where we need Tigers.”
 
Jeffrey Lord wrote an American Spectator piece, published July 30, 2013, on the Republican reluctance to fight and defund Obamacare, titled “The GOP: Rabbits or Tigers?” The rabbit-and-tiger language had been used before. “To finish off a soldier like Fritz, I needed tigers, not rabbits” was published in a 1934 magazine.
 
The idiomatic question “Are you a man or a mouse?” is similar to “rabbit or tiger?”
       
 
Google Books
Blackwood’s Magazine
Volume 236
1934
Pg. 733:
“To finish off a soldier like Fritz, I needed tigers, not rabbits. So I made tigers.”
 
Google Books
Reagan Diaries Volume 1:
January 1981-October 1985
By Ronald Reagan
Edited by Douglas Brinkley
New York, NY: HarperCollins Publishers
2009
Pg. 178:
(Tuesday, December 7, 1982—ed.)
No use—we took a beating 245 to 176—50 Republicans defecting. We had rabbits when we needed tigers
Pg. 212:
(Tuesday, April 5, 1983—ed.)
I had an unsatisfactory meeting with Repub. Senators on the budget committee. They are determined we must cut defense spending & increase domestic in order to get a budget passed. I’m opposed. We have rabbits where we need Tigers.
 
The American Spectator
The GOP: Rabbits or Tigers?
By Jeffrey Lord on 7.30.13 @ 6:09AM
Reagan, Thatcher and the real battle behind defunding Obamacare.
 
“We had rabbits when we needed tigers.” — Ronald Reagan writing in his diary of congressional Republicans.