This is neglecting the vacancy of the seat held by Lewis Powell, in which democrats literally invented a verb to prevent the first nominee from being confirmed, followed by paragon of moral virtue Ted Kennedy's feigned outrage at the fact that Douglas Ginsburg smoked pot in law school, and finally, a compromise by nominating a Justice who was basically a like for like replacement for Justice Powell.
If President Obama wants to nominate Brett Kavanaugh, Ted Cruz, or Miguel Estrada to replace Justice Scalia, we can talk. However, the odds are that he's going to nominate someone like Loretta Lynch or Sri Srinivasan.