My sole point is that if Rush ever used the expression "feets don't fail me now", the MSM would come down on him like a ton of bricks.
Is there anyone here who doubts it?
I totally agree ... if Rush had said it. But he didn't.
By your description, Berman is a democrat, so nothing will happen, whatever his intent.
Berman is close to my age. I'm sure he knows the phrase best in the same way I do. And I'm also sure he is not a racist or bigot.
The salient point being made here is the double standard at work. If a known conservative had made the same remark, likewise in an innocent way, he would be excoriated in the media. There would be calls by "civil rights" groups for the guy to be suspended or fired.
(BTW, I never heard of that album from the 1970s, which apparently was playing on the '30s-'40s expression. I didn't listen to that band.)