Puerto Ricans definitely live in a mixed economy, not the system that Marx described as capitalism, but it arguably shares the salient features of capitalism that Marx was addressing in the excerpt under discussion.
What is a mixed economy? The definition of capitalism I use is based on the capitalist mode of production, that is, how goods are made within a capitalist economy, viz. production to maximise exchange value over use value, the primacy of wage labour, private (and yes, this can include the state's) ownership of social means of production, and most social production is for the goal of capital accumulation.
In my opinion this is enough to say that a particular society is 'capitalist', though like all words there are variety of nuances and exceptions and additions that can be attached. Capitalism in my view neither necessitates nor excludes government controls on production, social democratic policies, taxes, the state (except for defense of private property) etc.
A good example of a capitalist (state capitalist) country is the Soviet Union.
Puerto Ricans definitely live in a mixed economy, not the system that Marx described as capitalism, but it arguably shares the salient features of capitalism that Marx was addressing in the excerpt under discussion.