I would argue that he had lttle political choice. As Lord Conrad points out, there were numerous populist and 3rd party movements who were far more lunatic than the New Dealers. Not only Russians and Germans were infatuated with 'modernism' and 'progressivism'.
There were scarcely a handful of prominent Americans by the mid-30s who were fully, and vocally, in favor of the classical liberal principles which had governed the U.S. intellectually since its inception.
Now, there is a revival of interest in America's founding ideas, which we can only hope reaches critical mass before an over-reaching State closes off all escape from some form of national socialism.