If they wanted a Kate Smith, they should have chosen a singer. Roseanne is not a singer, she’s a comedian. She was mocking what baseball players do at the end...it was stupid on the leaque’s part to ask a comedian to sing the anthem.
It couldn't be more obvious that she was deliberately mocking the NA with her screeching way off-key rendition, particularly given the fact that she's so lunatic left as to pick a prominent member of the Amerifan communist movement to be her VP in her presidential bid. Shouldn't require much brain power to see and understand this.
Maybe you didn't actually see the video? If not, here it is again...