It's usually just wrapped up in Law & Order BS.
To the tune of, "we better not let THEM be armed."
I mean, there was a ton of it wrapped up in Jim Crow all over the place. But that's easy pickings.
Just looking at the 20th century?
California's Mulford Act (It's even named after a Republican congressman) prohibited carrying loaded firearms in public. It was explicitly a response to the Black Panthers being openly armed when they patrolled neighborhoods, at one point marching on the capital building of California. It passed with bipartisan support and was signed by Governor Ronald Reagan, who vocally supported it. Thus began the slow descent of California into the neofeudal shithole it is today.
A year later, the Gun Control act of 1968 (publicized as a reaction to the mail-order firearms used to assassinate JFK and MLK) introduced the first four (later ten) federal prohibitions from owning a firearm in the U.S.
Of the four, three were definitely targeted at "undesirable populations."
Number one, felons.
I don't have to go into the ridiculous amount of things we've felonized over the years, do I? Nor go in depth as to who gets convicted more often?
Number two, drug users.
The 1968 version specifically highlights marijuana users.
It was a way to target BIPOC and hippies without coming right out and saying so.
As late as 2011, the ATF declared that holders of medical marijuana cards are automatically prohibited under this law.
Number three, adjudicated a mental defective or has been committed to any mental institution.
The DSM included all the LGBT spectrum and all the kinks in 1968.
There are mouth-breathing cousin gropers out there arguing this week that number three should be held against the LGBT community thanks to the Nashville shooting.
If I can say nothing else, I have to say that it's YOUR second amendment too, godsdammit.
Use it if you need to.
Don't if that's your desire.
But do NOT let the assholes try and take it from you.