Read other letters about this article
I imagine, someone out there has the definitive source. Digby's does come from the Franklin and Eleanor Roosevelt Institute. Hard pressed to find a more definitive source than that, I suppose, except that reference, within the text of a speech given by someone else, is kind of vague for my instincts. Still and all, it's a really "safe" one to use.
In poking around, what I'm finding is a story. And, invariably the quote is embedded within that story - although the principal characters (who FDR was speaking to) can change.
For example,
I'm reminded of something that Eleanor Roosevelt once told a group of us at a dinner. It was when she had first introduced A. Philip Randolph, a great labor leader back in the 1930s up to and including the civil rights movement.
And she introduced him to Franklin Delano Roosevelt for the first time at a dinner, and Roosevelt beseeched him to please tell him what he thought of the nation, what he thought of the plight of the Negro people and what did he think - where the nation was headed.
And A. Philip Randolph held forth and spoke eloquently on his thoughts, and at the end of it Roosevelt said to him, "You know, Mr. Randolph, I've heard everything you've said tonight, and I couldn't agree with you more. I agree with everything that you've said, including my capacity to be able to right many of these wrongs and to use my power and the bully pulpit." He said, "But I would ask one thing of you, Mr. Randolph, and that is go out and make me do it."
Google cache of Tavis Smiley PBS interview with Harry Belafonte in November 2008 below:
http://tinyurl.com/7hdl86
Alternatively,
Franklin Roosevelt’s example is useful here. After his election in 1932, FDR met with Sidney Hillman and other labor leaders, many of them active Socialists with whom he had worked over the past decade or more. Hillman and his allies arrived with plans they wanted the new President to implement. Roosevelt told them: “I agree with you, I want to do it, now make me do it.”
http://www.pnhp.org/news/2009/january/how_to_push_obama.php
Similarly, Amy Goodman of Democracy Now! in her interview with Adam Cohen
Google cache:
http://tinyurl.com/6vu5ww
Essentially, that's what I'm finding as I search. A story, repeated by others, in which the quote is embedded.
The quote also seems to take various forms.
I agree with you, I want to do it, now make me do it.
You've convinced me. I want to do it. Now make me do it.
The former is more "popular" than the latter.
So far, the longest list of quotes I can find attributed to FDR is the collection at:
http://www.brainyquote.com/quotes/authors/f/franklin_d_roosevelt.html
which does not include either of those noted above.
So, what we really have is an anecdote. And, what we really need is a research librarian who knows how to scare up historical anecdotes. Are you out there William Timberman?