the entire point of the court is to evaluate legislation against our constitution
That is not the entire point of SCOTUS. That is not even in the constitution; it is a power the court gave itself in Marbury v. Madison.
Most SCOTUS decisions are judging appeals against federal law (including the constitution). Occasionally they rule a federal law unconstitutional, but not usually.
It was Mitch McConnell and the Republics that blocked Merrick Garland, not the Democrats.