Total votes for and against the Republican Nominees (Roberts in 2005, Alito in 2006): 136 for, 64 against.
Total votes for and against the Democratic Nominees (Sotomayor in 2009, Kagan in 2010): 131 for, 68 against.
Very close. Plus, if you take out the votes of Democratic Senators for Republican nominees where the Senators have since said that if they could do it again they would have voted “no”, the numbers are almost exactly the same.
Source: The Roberts vote was 78-22; Alito was 58-42; Sotomayor was 68-31, and Kagan was 63-37.