The “Saturday night special” is in part a linguistic descendant of the racist phrase "Niggertown Saturday Night." The obvious implication of the phrase "Saturday night special" is that it is a gun used by "niggers" to shoot each other with during their wild Saturday nights. No one denies that the people disarmed by a "Saturday night special" ban would be predominantly poor and non-white.
Liberal politicians tell yuppie and soccer mom constituents that they will ban Saturday Night Specials, which makes the yuppies and soccer moms feel all warm and fuzzy.
Of course, banning inexpensive handguns deprives poor people of their most effective defense against Pachuco boys and other criminals.