But why?!

He toured with Rockabilly artists more than other country singers.

Yeah, just as an example -

Marty “Big Iron” Robbins released a song in 1966 called “Ain’t I Right” that said people who came down to southern towns last summer to show people a new way of life were actually a bunch of secret Communists who didn’t care about America and just wanted to sow discord.

Some context: in the summer of 1964, a bunch of civil rights activists went down to southern states to register people to vote for an event called “Freedom Summer,” which led to them being harassed by local police and eventually at least 3 of them being murdered by the KKK. This was a huge headline dominating story that made the American mainstream actually start paying attention to the civil rights movement and start looking at how bad racism in the south had gotten, so Robbins was totally reacting to and trying to push against that change in popular opinion when he released that song.

Oh, you poor soul.

Here’s the wikipedia, if you wanna read.

And here’s a video about the history of slavery and its after-effects that is kind of relevant.

The tl;dr is that there were laws, like vagrancy (i.e. not having a job), that were vague and applied to “everybody” but realistically only applied to black people through legal jiu jitsu and selective blindness on the part of police. Sundown towns are known as such for that behavior. They were (are) very unwelcoming if you’re not white.