This spurious James Madison ten commandments quote has been around for a long time, and, despite the fact that even David Barton, the most popular of all Christian nationalist history revisionists (and head of the pro-Cruz super PAC Keep the Promise), has admitted that this quote is "unconfirmed" and now tells the readers of his website to refrain from using it, it continues to be used as much as ever.
While others have traced the first appearance of this bogus Madison quote back to a 1958 calendar, I was determined to hunt down its exact source and prove once and for all that this quote did not come from James Madison. I began looking into this back in 2007, and after quite a bit of hunting found what I was certain was the exact source of the misquote in 2009 - a speech that conservative leader Clarence Manion was traveling the country delivering in the early 1950s. But as certain as I was that Manion's speech was the original source of this misquote, there was on little problem - one of the sources cited by David Barton for the quote was a book from 1939, thirteen years before Manion even began giving this speech. Further research, however, indicated that Barton's 1939 source was fabricated. With Barton's alleged 1939 source out of the way, there is no question that the source of the infamous Madison ten commandments quote was Clarence Manion's speech, and I'd stake the whole future of American civilization on that.
"Cruz Loves God and James Madison," and Phil Robertson has a Fake James Madison Quote to Back That Up