Looking at it again with fresher eyes, Carpenter was implying that the aliens were exploiting the earth like imperialists do in third-world countries. While not overtly leftist i.e. people aren't talking theory and such, the film oozes working class sentiment and is super cynical and punched at Reagan and capitalism.
Everyone should watch it!
It really does! The movie still feels just as fresh and relevant in 2021 as it did back in 1988. Guess that says a lot, huh? Also has one of the absolute best fight scenes in cinema history. Just two dudes punching and kicking the shit out of each other until exhaustion for almost 10 minutes.