That is not what the ********* Bronco "fans" looked like, atleast not in Orange County where they made up by far the most annoying of the fanbases that would watch games at the bars. They would roll into the sports bars for those 1PM games and you would immediately see the bartender stock up on mint and sliced pineapples for all the mojitos and mai-tai's the guys would order. And who cares if one of the early games was coming down to the final drive, they wanted all those TV's with sound turned to the Broncos.
To this day, I still have no idea how so many people with no connection to Denver whatsoever became Broncos fans.
You are probably too young to remember what happened in 1977.
The Broncos were the most pathetic professional football team for the first 15 years of its existence, from 1960 to 1975. They hired a new coach in 1976 as I recall, and he took the team to their first winning record (either ever, or second, can't remember). EDIT: Looking at the Wiki page linked below, the first winning record was in 1972; the team showed an upsurge under John Ralston in the early and mid-70s, then hired Red Miller and the team took off after him in 1977.
Everyone, and I mean
EVERYONE, jumped onto the Denver bandwagon in 1977. They had the "Orange Crush" campaign going full-swing, and we were all watching this **** team for so long become a powerhouse. They were no match for Dallas in the Super Bowl, but they were clearly the best team in the AFC that season.
You couldn't find Denver gear anywhere. I went to some sports shop that season and asked for a Denver pennant; there weren't any. Everything got sold out.
If current fans don't have a geographical or family connection to Denver, I suspect what happened in 1977 to be the source of the widespread fandom, handed down to the succeeding generations. It was pretty crazy back then...I think Denver may have been the last team of its era to finally dig its way out of the cellar.
You may recall that Tampa Bay in 2003 and New Orleans in 2010 had similar bandwagon movements, but never to the extent that Denver had in 1977.
https://en.wikipedia.org/wiki/Denver_Broncos