I kinda hoped that the last line would kinda give it away, but I should make clear at this point that I am
not butterflying away Communist reactions. Those reactions are going to be very ugly. They just haven't happened yet
As for the hamfisted way the referendum was run, the Allies really didn't have a hand in running things on the ground (such as, perhaps, the number of polling stations...); that was left to the Italian government. The extent to which the Allies were officially involved remained ambiguous ITTL, and although
I know the scope of that extent I will leave it ambiguous here. The more explicitly communist nature of the insurgency in the RSI (Bologna Soviet) and the larger scope of the damage done lead to a greater fear of communism in Italy; and certainly not without merit.
McCarthy will soon be a very busy man...
ETA: From the OTL perspective of an OOC monarchist, I personally loathe the House of Savoy and think that Italian unification was a mistake in the first place. But this seemed like an interesting POD...