I think it's interesting how American ideals have been portrayed in so many ways, from heroes like The Fantastic 4 and Iron Man embracing science and technology, to heroes like Superman and Captain America representing physical ideals, to guys like Batman and Punisher working outside the laws to achieve their goals while still sticking to their self imposed rules and ideals of justice.
But. Every superhero - every superhero - is extralegal. The Commissioner may call Batman with the Bat Signal, but Batman is utterly divorced from due process. He needs no warrants. He need not adhere to rules of engagement. And he is always called in when the police are helpless. You can extend that on down to James Bond - "license to kill" is a shitty fucking thing to grant someone. And there's always some supervillain that exceeds due process' ability to deal with the adversary. It's interesting that the same people that will rail against warrantless surveillance and drone strikes will chomp down on popcorn while watching the Dark Knight or James Bond or fuck - Mr. Incredible.
Alternately, it's a holdover from a culture of honor, where violence not sanctioned by institutions was encouraged because institutions were weak and the way you kept yourself, your family and your stuff safe was to have a reputation for violence. (The article I linked to isn't great, but there's some kind of unrelated Christian use of the term "culture of honor" that crowds the Google results and I couldn't find any survey papers.) That's regressive too in a modern context, but it's not the same as fascism. A fascist superhero would be backed by institutions, fascism being all about gaining power by surrendering to the collective, hence taking its name from the fasces.
That article links to a straight up bullshit study. Cortisol levels take weeks or months to crest. They take fuckin' 10 minutes just to test. Delaware?Participants were 83 University of Michigan white male undergraduates (42 northern, 41 southern) who were recruited by telephone and paid $5 for their time. Students who had lived in the South for a period of at least 6 years were considered southern. The South was defined as census divisions 5, 6, and 7. This includes the states of Delaware, Maryland, West Virginia, Virginia, North Carolina, South Carolina, Georgia, Florida, Kentucky, Tennessee, Alabama, Mississippi, Arkansas, Oklahoma, Louisiana, and Texas.