Law: Mussolini became the Prime Minister of Italy in 1922. During the next seven years he slowly transformed Italy into a totalitarian state. This was partially achieved by introducing several new laws within the government.
Acerbo Electoral Law, (July 1923): It stated that "any party gaining more votes than any of its rivals, providing that it gained at least 25% of the total votes, would be entitled 2/3 of the seats in the assembly." In the following year's election, this law ensured the Fascist domination in the parliament.
In 1926, after the assassination of the Socialist leader Giacomo Matteotti (most likely done by Mussolinis' own men) and several assassination attempts against himself Mussolini enforced a new law on association, in which he outlawed all his political opposition.
In 1928, a new law abolished universal suffrage and restricted parliamentary election to candidates officially nominated by the Fascist Grand Council. By 1929, the Italian parliament consisted of only the Fascists.
Also in 1929, the parliament granted Mussolini the power to rule by decree. He immediately ordered a series of decrees which transferred to him complete legislative authority. The king was forced to accept him as the permanent Prime Minister of Italy.
Law Enforcement: despite of Mussolinis' authorities, not everyone agreed with him. Therefore he also needed some organizations to make sure that his laws were "accepted".
The earliest form of Fascist law enforcement was the Blackshirts. Strictly speaking, they were merely an organized armed gang. But their anti-socialistic actions (especially during the Socialist general strike in 1922) made the Fascist popular among the upper and middle classes. This was essential to their eventual success.
In order to deal with Mussolini's opposition after he became the Prime Minister, Mussolini set up a secret police force called the OVRA. They built concentration camps on Lipari Islands for his opponents. From 1925 to 1926 more than 10.000 antiFascists were arrested, executed or exiled. Workers' unions were banned and the press was censored at the same time.
The Fascist Militia (MVSN) also had certain contribution to the Fascist electoral success in April 1924; they won 66.3% of the "valid" votes due to their "strong-arm" method.
Although by the end of 1920s, the parliament still existed and the King Victor Emmanuel Ill was still sitting on his throne, the government and it power had fell in the hands of the Fascist Party. It seems, by means of law and law enforcement, Benito Mussolini had achieved the level where "everything within the state, nothing outside the state, nothing against the state."