Thanks for finding and posting this.It just shows that there have always been defeatists and naysayers.
I think Dos Passos had ceased to be a communist at this point. He was one of those disillusioned by the Spanish Civil War who then became a "premature anti-Stalinist" and was denounced by his former comrades for breaking with the Party line.
Why am I reminded of Ann Coulter's book Treason ??