The presumptive Republican presidential nominee tweeted early this morning that Ginsburg's "mind is shot" and should "resign."
Ginsburg, 83, hasn't shied from blasting the business mogul in recent interviews.
"He is a faker," she said of Trump on Monday on CNN. "He has no consistency about him. He says whatever comes into his head at the moment. He really has an ego ... How has he gotten away with not turning over his tax returns? The press seems to be very gentle with him on that."
She told The New York Times that a Trump presidency would be unimaginable for the country and the Supreme Court.
"I can’t imagine what this place would be — I can't imagine what the country would be with Donald Trump as our president," she told the Times. "For the country, it could be four years. For the court, it could be — I don’t even want to contemplate that."
She jokingly added that her late husband would suggest moving to New Zealand if he were still alive and witnessed a Trump victory in November.
Trump fired back Tuesday, telling the Times that her comments were "highly inappropriate" and "a disgrace to the court."
House Speaker Paul Ryan said Ginsburg's comments showed bias during a CNN town hall interview yesterday evening.
"For someone on the Supreme Court who is going to be calling balls and strikes in the future based upon what the next president and Congress does, that strikes me as inherently biased and out of the realm."