Socialist theories are in practice all over the US. The army, the police, the roads, bridges, sewers, most schools, courts, parks...I could go on for hours. Socialism does not mean ONLY that the state owns the means of production - socialism is also when the state (i.e. "the government") "regulates" the means of production. Every functioning government in the world does that, including the US. How that regulation is done is where people get hung up on defining socialism.