Towards the end of the movie, Bart convinces the townsfolk to rise up and fight off the bandits by telling them, "you'd do it for Randolph Scott." Judging by their reaction, they think really highly of Randolph Scott, and agree to his plan. But you can be forgiven for scratching your head and asking, "who the heck is Randolph Scott?" (We admit, we did it the first time was saw the movie, too.)
As it turns out, Scott was a successful actor and leading man whose career stretched from the silent era until the early 1960s. He grew up in North Carolina, served in the army during World War I, and then came out to Hollywood in the 1920s to try his hand as an actor.
It worked out pretty well.
He had over 106 credits to his name, and as you may have suspected, a lot of them were Western movies. Like, a whole lot. None of them are outstanding classics, but they were pretty good. And Scott had that square-jawed leading man thing going on that made everyone believe that he was the good sheriff out to put those rustlers behind bars.
Brooks, as part of his ritualized de-pantsing of the entire Western genre, must have figured he was too big of a name to let slide. The joke hits right toward the end, not only invoking all of Scott's old oaters, but also quietly suggesting that they might not be as classic as the townspeople clearly seem to think.