Republicans are basically now saying that a Republican president and Senate should select a justice because they are the same party. It wasn’t always this way. It used to be that the votes were based on whether the nominee was qualified, not if you agreed with all of their policies. 30 years ago (and under different nominating circumstances) I would have voted for Gorsuch even though I don’t agree with him on much. He’s qualified. I wouldn’t have voted for Kavanaugh since the allegations against him were not fully investigated.
Let’s look at some controversial nominations which show votes didn’t use to be almost exclusively on party lines. When Robert Bork was nominated, two Democrats voted for him and six Republicans voted against him. When Clarence Thomas was confirmed, 11 Democrats voted for him. He would not have been approved without them. Two Republicans opposed him.
Here are all the votes for justices that have been confirmed since 1970:
|Rehnquist (chief justice)||65-33||1986|
Though the votes got closer, there were still senators that voted for justices nominated by the other party. For example, 22 Democrats voted for Roberts. Lindsey Graham was one of five Republicans who voted for Kagan.
Because of Republican hypocrisy on Garland and the next Trump nominee, votes will be strictly along party lines indefinitely.
Confirmation vote information was taken from here.