No definitions have yet mentioned the Midwest bro's in particular, but broism has become rampant in the Midwest. They are on every Big Ten campus (especially frats.)
This particular variety of bro always drinks the cheapest beer or liquor and may or may not smoke weed.
The clothes they wear might not be as expensive as the clothes people wear on the coasts, but these bro's are still wearing the most expensive clothes that they can. They also pimp their rides out as much as they can. They compete with money the same way, even if they have less of it.
Hobbies are the same-- weightlifting, pick-up basketball, golf, and especially, frolf.
Even though they behave as belligerently and are as disrespectful towards women as bro's anywhere else, they go to church once or twice a month. They are obsessive sports fans and if they go to a larger college (especially Big Ten) they will attend literally every home football game (if not every away game) and a very high amount of basketball games as well. They will be drunk for every game.
Chicago is bro central for the midwest, but Minneapolis/St. Paul has many bro's as well. Universities in Ohio are also notorious for bro's especially OSU and Miami U.
Don't believe you are safe from the bro stereotype if you move to the midwest!
Female one: "Ugh, why are there so many bro's at that party?"
Female two: "Yeah, it feels like we're still in San Bernadino."