Today, William Jennings Bryan is usually thought of as the hapless defender of religious fundamentalism against Clarence Darrow during the Scopes trial. In his day, however, Bryan was a fiery populist colossus fighting for cheap money and the increased regulation of business–most notably, railroads. That’s a left-wing agenda. How could the two mix?
Populism is an attitude, not a specific program. Populism doesn’t recognize any consistent difference between right-wing and left-wing measures. A populist wants to take on the establishment and use the powers of the government to help the benighted little guy. More often than not, that requires economic measures which we would associate with the left. The bottom line, therefore, is that the inconsistency that we would perceive here is in our own minds, not Bryan’s.