I suppose it is possible that he never said that, we have to take a journalist's word, who wrote for American Atheists news journal, and who definitely has a bias towards the issue being discussed. That snopes site had a lot of contrasting viewpoints and by no means was the opinion you quoted the only one regarding the authenticity of this matter. Richard Dawkins refers to this actual quote in the God Delusion and says perhaps it can be taken with a grain of salt. That being sad, I would suggest you take it from the horses mouth, and check out what he has to say about the claims against him, which I feel, he has made a fairly decent rebuke of the charges against his lying. Specific corroborating evidence contained in the presidential library confirming the meeting of Sherman and Bush as well as letters submitted to President Bush and responded to by his legal counsel concerning that meeting are presented.  Here is a small snippet from the page, which should be read in its entirety to understand the whole story.

  "The letter from Mr. Murray to the Members of Congress is from a file identified as White House Office of Records Management, Subject Code RM, Document Number 157715 CU.  This document is a letter that Jon Murray sent to every Member of Congress on February 21, 1990.  In this letter, Mr. Murray describes the news conference that I attended, quotes exactly the conversation between Mr. Bush and myself, and then states:

Subsequent to these astonishing statements, I wrote to (then) Vice President Bush demanding a clarification of these remarks.  More than two months later, on February 21, 1989, C. Boyden Gray, Counsel to the President, wrote to me from the White House as follows:

Your letter of December 19, 1988, to President Bush has been referred to me for reply.  As you are aware, the President is a religious man who neither supports atheism nor believes that atheism should be unnecessarily encouraged or supported by the government.  Needless to say, the President supports the Constitution and laws of the United States, and you may rest assured that this Administration will proceed at all times with due regard for the legal rights of atheists, as will as others with whom the President disagrees.

This letter was a clear admission by the President, through his counsel, that he had indeed made the remarks and was not backing down from them."

 

Here is Sherman's site containing the rebuttal:sherman

That being said, the question I asked doesn't have to be the one the RRS asks, but was merely one I thought was important. Something can be said about using a controversial quote in a debate question that might lead to a lessening of credibility of the questioner's reputation. Thanks for bringing this up.