Here’s a Congressional Research Service report setting forth 154 instances in the 10 years from 1987 to 1996 in which the Senate failed to give a hearing (much less a final floor vote) to a presidential nominee. As I understand it, there is nothing special about that 10-year period (eight years of which featured Democratic control of the Senate).
As I’ve pointed out time and again, there is no Appointments Clause that applies uniquely to Supreme Court nominations. Rather, the same provision applies equally to Supreme Court nominations and the run of other nominations. Anyone who really believes that the Constitution somehow requires the Senate to hold a hearing and to take a floor vote on a nomination doesn’t know up from down about the Constitution or about the Senate’s longstanding practices that are consistent with the free operation that the Constitution accords it.
(By contrast, it is fair game to make political objections to how the Senate chooses to exercise its power.)