Guys, you think that italians take politics much more seriously than they actually do.
(I should know, I am one of them)
Both socialist and communinst italians were actually lukewarm politicians, much more interesting in internal bickering and quiet living that in Doing The Revolution.
Even with a Popular front majority, Italy would be inside the Marshall plan and inside NATO, whle trying to run under-the-table compromise agreements with all the players in the area (exactly as per OTL).
Also consider that "majority" in the post war italian parliament is much more shaky that otherwhere, both because the legislature structure has been shaped to avoid a one-party-rules-it-all scenario (they had their fingers burnt on fascism) and because double backing and vote selling are considered part of the game. Unlike other countries, a politician is not burnt if he switches front amid legislature, and is likely to be re-elected in the next elections