Do you know how laws are often interpreted? It's asking what is the faith and meaning of the law, NOT what is literally written in paper. This means past precedents are incredibly important for defining what a law is. Refusing to hold a vote for a nomination of a qualified supreme court justice is not against the law on paper, but it is against the meaning of the laws and the precedents of how the president interacts with the supreme court.

It is not the senates job to decide if a nominee is worthy of being nominated, or if the president should make a nomination. It is their job to vote on the nominee. They did not do that.