My professional life has been devoted to explaining this photo to the uninitiated. To an American, an anti-immigrant message such as this (Enough immigrants, homes and work for Italians) accompanied by a swastika makes sense. But, it is signed by an Ultra group, AS Roma Ultras, associated with the AS Roma soccer team. The extreme nature of the Ultras aside, this is a group of politically and intellectually active sports fans spreading a rightist message in their city, and in the name of their favorite team. Thus, there are many layers of analysis.
Sports fans in America are rather less political. The only impact sports have on our politics is that all candidates are or pretend to be avid fans of the home team for publicity. Given the martial aspect of sports, though, it is understandable that nationalism rather than Marxism tends to pervade hooliganism, etc.