The opposite is true. He shouted his support for the maximal left-labor program whenever he got the chance.
http://www.npr.org/templates/story/story.php?storyId=5241771
Fresh Air from WHYY, March 2, 2006 · A Godly Hero: The Life of William Jennings Bryan is the new history from Michael Kazin. Bryan has been described by Kazin as "one of the most crucial Americans never to win a presidential election."
http://www.washingtonmonthly.com/features/2006/0603.kilgore.html
The Gospel of William Jennings Bryan The Great Commoner wasn't a progressive despite his traditionalism —but because of it.
By Ed Kilgore
Upon hearing of the death of William Jennings Bryan in 1925, the Socialist leader Eugene Debs sadly commented that the iconic populist over the course of his lifetime "grew more and more conservative until finally he stood before the country as a champion of everything reactionary in our political and social life."
A Godly Hero by Michael Kazin Knopf, $30.00
This is the still-prevailing judgment that led Georgetown University's Michael Kazin to undertake a new biography of Bryan. Kazin's mission in A Godly Hero: The Life of William Jennings Bryan is to establish that the Great Commoner was the same man with the same principles, and much the same following, during and between the two famous bookends of his career: the 1896 "Cross of Gold" speech that launched his tumultuous first presidential campaign, and the Scopes "Monkey Trial" a few days before his death. Throughout Bryan's career, Kazin shows, he embodied a "creed that married democracy and pietism in a romantic gospel that borrowed equally from Jefferson and Jesus"—a creed that today's self-styled populists of the left and the right largely reject.
In seeking to rediscover Bryan as the paragon of a highly integrated world-view, and not a paradox combining "progressive" and "reactionary" impulses, Kazin devotes a significant portion of his book to "Bryan's people," the vast array of largely middle-class and typically Protestant folk who looked to him for political and moral direction over three decades. Like Bryan himself, his devoted followers (upon whose correspondence with Will and Mary Bryan Kazin draws heavily) were characterized by a highly moralistic and Bible-inflected approach to politics and a very direct and practical approach to the implications of their faith. The trusts, the railroad owners, the Wall Street speculators, and the urban bosses who populated Bryan's demonology were deplored as the idolatrous oppressors of godly people, not simply as products of a flawed economic system. <SNIP>
-- Michael Pugliese