It certainly sounds like it to me.
I am not a lawyer or a politician, and maybe a state judge or a governor can defy a branch of the federal government, but Governor Wallace certainly didn't succeed.
Perhaps my logic is flawed and Congress isn't the SCOTUS but the situation reminds me of a supreme justice issuing a stay of execution.
Maybe that's what's called for, a stay of execution because I don't think it can be called anything else.