Malcolm,
 
the association of Progressivism with Fascism does not require a Whiggish  
interpretation -- if one accepts your dating of the intellectual roots of  
Fascism as the 1880s, then it coincides with the emergence of the first  
Progressive Era (although, if one accepts that, at some level at  least, the 
Progressives emerged from the ruins of Populism, that lineage  stretches back 
even further); if one takes the beginnings of the Fascist  movement as 1921 
or thereabouts, then it emerges near the end of the first  Progressive Era, 
and offers a glimpse into the second.  Either way, and  whatever the 
direction of intellectual transmission, such ideas were freely  discussed.
 
Yes, there are indeed commonalities, but remember, this discussion (such as 
 it has become) began with the attribution of Fascist leanings to Pareto, 
and  quickly devolved into an accusation against Hayek.  By the time it 
reached  the Progressives, it seems as though we achieved at least five degrees 
of  separation.  Typically the game ends at six, I have been told!
 
CM