Mussolini came to power in Italy because of widespread social and economic unrest in the country following World War I.
Countries tend to become fascist because their people are worried about the breakdown of society. This is what was going on in places like Italy and Germany after WWI. This was what led to the rise of fascist dictators like Mussolini (and like Hitler in Germany).
In Italy after WWII, there was a great degree of chaos. There were many who were worried that socialists and communists were going to take over the country as a result of this chaos. Because of this fear, many turned to support the fascists since they promised to bring order back to the country.