At first glance, I think a lot of people who are predisposed to not like Mao would probably interpret the slogan “political power grows out of the barrel of a gun” as indicative of a Maoist penchant for violence, or a preference for armed coercion over democracy, or something of that nature. What it actually is though is a very succinct identification of the material basis of state power.
While one might be tempted to see an abstract system of laws, rights and obligations as being the driving force behind politics and civic life, Mao’s statement identifies the reason that, for example, laws and declarations issued by the United States Congress can dictate aspects of the daily lives of hundreds of millions of people, while those issued by, say, Emperor Norton can not. The weight behind any prevailing political and legal system is ultimately provided by guns, or rather — what Mao is signifying with his reference to guns — the ability of a certain class of people to use force to assert their interests over the rest of the population (of course the Maoist analysis of the material mechanisms underlying state power goes far beyond just weapons, but, for the purposes of a one-sentence slogan, “the barrel of a gun” sums it up pretty well). All of the authority emanating from the hallowed halls of Congress would vanish were it not for the existence of a police and military apparatus propping it up — and as we can see through an analysis of the domestic situation in the United States, the rights and freedoms supposedly guaranteed by this body mean nothing for the members of the population that the police and military apparatus have no desire to defend, or have a desire to actively persecute.
This understanding reveals the limitations behind efforts at legal reformism. Because although changes in laws can indeed have incredibly transformative effects on society, these changes can only be achieved insofar as the ruling class — again, that is the group of people that has the power to assert its interests over the rest of the population — has the desire and ability to implement them. Therefore, the changes that can be achieved through legal reform are limited to changes that, in the short or long term, benefit the ruling class. In order for changes to be made that are entirely in the interests of the working class (and not just reformist concessions to workers that the ruling class is forced to grant, often temporarily, in the face of massive popular pressure), then the working class must become the ruling class. The working class must become the class with the power to assert its interests, and to do that, the working class must be able to break the power that the bourgeoisie derives from its military force. Until the working class is able to assert and defend its interests by force, any gains that they can make are completely dependent on the complicity of the capitalist class.
As the defeat of Salvador Allende’s government in Chile clearly demonstrated, even seizing legal power in an election will not lead to the liberation of workers if the bourgeoisie still hold military dominance. The power supposedly conferred upon Allende by the legal system counted for nothing, because Allende’s goals were contrary to the interests of the bourgeoisie — which remained the one class that was able to assert its dominance in the country, and remained so because of its ability to wield military force. The workers’ movement did not have the armed power that the forces of the bourgeoisie did, and so its members were defeated and massacred. Here, the message of “political power flows from the barrel of a gun” dovetails with that of another famous Maoist phrase “without a people’s army, the people have nothing”. Rights, freedoms, and laws only exist insofar as there exists the power to enforce them, and this power does indeed grow from the barrel of a gun. No matter how much one reveres the “rule of law” in the abstract, ultimately the law is a paper shield, and will not stand against bullets.